The Caves of Nam Nao National Park,

Phetchabun

 

Abstract

 

Between
December 2003 and January 2006 there have been four Shepton Mallet Caving Club
expeditions to the Nam Nao National Park in Phetchabun province. A total of ten
weeks have been spent in the field exploring and surveying the caves.  The
longest cave in the national park, Tham Yai Nam Nao, has been surveyed to a
length of 9.8km.  Several other major caves have been found including Tham Phaya
Naak/Tham Wi Mahn Mek/Tham Nop Pa Krauw (1,285m, -133m), Tham Bah Dahn (655m)
and Tham Monhwa (350m).  

 

Dedication

 

This report is dedicated to the memory of David 'Fig'
Briggs.

 

Introduction

 

After three
expeditions to Umphang in Tak province on the western border of Thailand with
Myanmar, between 2000 and 2003, the Shepton Mallet Caving Club started looking
for another area to explore.  It must be admitted that we were also looking for
a more 'civilised' area with decent hotels, a variety of restaurants and a more
lively night life.

 

John
Dunkley's 'Caves of Thailand' book was consulted along with a list of Thailand's
longest caves.  It was noted that Tham Yai Nam Nao in the Nam Nao National Park
had not had a follow up trip since the original exploration in 1992.  We had
already been caving in this region on our first Thailand expedition in February
2000 and again in February 2002.  Although Tham Yai Nam Nao had not been visited
we had been to the other well-known cave in the Park, Tham Par Hong.  In
addition we had stayed at the hotel in Lom Sak and knew that access to the park
was fairly easy.

 

We had
intended for our first visit, in December 2003, to be part of a reconnaissance
of the whole Phetchabun Mountain range from Nam Nao National Park in the north
to Khao Yai National Park (Nakhon Ratchasima province) in the south.  However,
Tham Yai Nam Nao and the surrounding hills were found to be so promising that we
stayed here for the duration of our visit.  This first trip was quickly followed
by another visit in April 2004 and a month long expedition in January 2005.  The
most recent trip has been in January 2006 and we now feel that enough work has
been done to justify publishing this detailed report.

 

This report
includes information on all the caves, stream sinks, digs, etc. that we have
found on the expeditions.  General information on the Nam Nao National Park,
accommodation, noodle shops, etc. is also given, but it should be remembered
that this sort of 'guidebook' information soon becomes out of date.

 

Nam Nao National Park

 

The Nam Nao
National Park is located in the north of Phetchabun province.  It is about 400km
north of Bangkok and 75km from Laos.  The park covers 966 square kilometres and
was designated on the 4 May 1972.  The park straddles the watershed between
north-central Thailand (the Pa Sak River basin) and north eastern
Thailand (Mekhong River basin). Its part of the Phetchabun Mountain range that
runs south from Phu Luang mountain in Loei province and forms the border between
Chaiyaphum and Phetchabun provinces. The park headquarters are located about
50km east of Lom Sak on the H12 road.  This has a small museum and library,
administrative buildings, the usual food stalls, a campsite and there are
several bungalows that can be rented. 

 

The National Park is part of the
5,948 square kilometre Western Isaan Forest Complex of eight contiguous
protected areas.  This area stands out as being the only sizeable expanse of
closed forest remaining in the region. The protected areas are the Phu Kheio,
Tapo-Huay Yai, Phu Pha Daeng and Pha Phueng Wildlife Sanctuaries and the Tad
Mok, Nam Nao, Phu Pha Man and Phu Kradung National Parks.

 

At 1,271m Khao Phu Phajit is the highest mountain in the
Park. There are many rivers and streams within this important watershed area. 
The Pa Sak River (which flows south through Lom Sak and Phetchabun town) is one
of these and it eventually joins the Chao Phraya River in Ayutthaya before
flowing into the Gulf of Thailand just south of Bangkok.  Other important rivers
are the Pong and Loei rivers (which flow north from the park) and the Khon Kaen
and Nam Churn rivers (which flow east into the Ubonrat Dam). All these rivers
eventually join the Mekhong River which flows into the South China Sea in
Vietnam.

 

The mountains and forests create
a cooler climate in the Park, particularly during the night and early morning.
The daytime temperatures are very pleasant with an average annual temperature of
25°C. The rainy season is between July and October. The cold season can be very
cold (for Thailand), sometimes even with a frost and temperatures as low as 0°C.
The coldest month is November.  We have experienced comfortable temperatures of
20-25°C in January, but in April it has been 30-35°C and occasionally hotter. 

 

The forest of Nam Nao contains
many different forest types, including dipterocarp, deciduous, evergreen, hill
evergreen and pine forest. The karst areas we have been exploring, in the north
of the Park, are mainly open bamboo and dipterocarp forest.  In the bottom of
the dolines there are often old signs of agriculture such as banana
plantations.  In the past the forest has been commercially exploited.

The forest structure within Nam Nao provides good shelter for 120 mammal
species, including elephant, marbled cat, Asiatic black bear, Malayan sun bear,
tiger, leopard, Asian jackal, Lar gibbon, fox, porcupine, wild pig, guar, mouse
deer and rabbits. These are distributed throughout the park. The last sighting
of rhinoceros in Thailand was in the neighbouring Phu Kheio Wildlife Sanctuary
in 1979.  The signs of elephants (dung, knocked over trees and footprints) are
commonly found in the area we have been exploring.  Wild elephants have been
seen twice and heard once.  The first incident was when elephants were heard in
Doline 725 which was nicknamed 'Elephant' doline as a result.  The following
year two people on foot got within 20m of an elephant before seeing it, but
fortunately it ran away.  Finally an elephant was seen after dark beside the H12
road near the Park headquarters and it was possible to get within 5m of this
animal.  The monk's campsite at Tham Nop Pa Krauw was destroyed by elephants one
night in 2005 and they were also heard here by the monks in 2006.

There are 203 confirmed species of birds in the park. It is claimed that when
walking the trails you are likely to see birds such as parrots, hornbills,
warblers, babblers and siamese firebacks. However, we have found the forest to
be very quiet and little bird life has been seen by us.  Three hundred and forty
or so butterfly species are reported to have been found in the park. These have
not been studied by us, but several large Troides birdwing butterflies
were seen flying along the stream in the 'Elephant' doline.

 

The Park is under pressure from the
surrounding villages. The hills to the north of the park, along the H2216 road,
have been completely cleared of forest and are used for growing maize, cabbage,
etc.  This clearance has been carried out by Thais rather than hilltribes such
as the Hmong.  The clearance probably began in the 1970s when the road was
constructed, forest was cleared and people were settled in the area to deny the
region to the Communist insurgents.  The nearby Pha Luang (to the north) and Phu
Hin Rong Kla and Khao Kho mountain ranges (to the west of the Pa Sak valley)
were Communist strongholds until the early 1980s.  Local farmers also hunt
within the park boundaries.  We have found a muzzle-loading rifle hidden amongst
limestone rocks in the Park and one farmer, met at a nearby noodle shop,
admitted hunting birds within the Park boundaries.  There are indications that
there used to be agriculture in the Park with old banana plantations in the
floors of Doline 715 and 'Banana' doline and degraded cart tracks.  The only
agricultural activity we have seen are cows and buffalo being grazed at the
edges of the park and in the 'Banana' doline.  In the dry season there are often
fires which clear the dry bamboo leaves from the forest floor without causing
too much destruction to the rest of the vegetation.  It is not known if these
fires are set by villagers or are caused naturally.

 

Accommodation and General
Information

 

Although Tham
Yai Nam Nao is easily accessible by road it is unfortunately a long way from the
nearest town.  The Shepton Mallet Caving Club expeditions have been based in Lom
Sak which is a 75km (one hour) drive from the cave.  In Lom Sak there is one 3
star hotel, the Nattirat Grand Hotel, which charges 695 baht per room (January
2006). This price doubles over the New Year and Songkran holiday period and
pre-booking is advised at these times.  The Nattirat is located on the road
heading north towards Loei.  The hotel is a soul-less place to eat and drink,
but fortunately there are good restaurants, a karaoke bar and a 'singing girls'
bar ('nak rong pu ying') close by.  Be warned that an evening spent in the
karaoke or singing girls bar can make the next day's caving hard work.  Lom Sak
is a fairly large town with many other eating places, markets, newsagents (the
English language papers arrive around 13:00), hospital, etc. There is a direct
bus service to Bangkok which costs 250 baht one way.

 

Outside of
Lom Sak there are a couple of 'resorts' on Khao Khor and one near Lom Kao, but
these tend to be a lot more expensive, are remote from the town's attractions
and are even further from the caves. There are hotels on the other side of the
mountains in Chumphae, but these are further away than Lom Sak and the access
roads are even worse.

 

Another option is to turn up with a
cool box of food and ask in the villages near the cave if anyone has a spare
room or house.  This requires some proficiency in spoken Thai, but you are
almost certain of finding lodgings.  We were offered the chance to stay at a
farm by someone who we met in the noodle shop.  Although staying locally would
save a lot of driving it must be remembered that the accommodation will be
fairly primitive (squat toilets, cold water showers), you will have to be on
your best behaviour and the village is likely to be completely dead after 9 pm.

 

Somewhere
between Tham Yai Nam Nao and Ban Nam Nao there is a 'campsite'.  This is
actually a small resort with some basic bungalows available to rent. I have seen
the website and have a business card for the resort, but have not managed to
work out exactly where it is.  A final possible source of accommodation is the
National Park headquarters on H12 where there are tents and bungalows
available.  These are almost certainly going to be fully booked at busy holiday
times and the Park headquarters is considerably further by road from Tham Yai
Nam Nao than the hotel in Lom Sak.

 

To reach Tham
Yai Nam Nao from Lom Sak you need to turn left out of the Nattirat Grand Hotel
and head towards Loei.  This road, the H201, is a fairly fast road with perhaps
half of it being dual carriageway.  A few kilometres north of the town the Lom
Sak bypass road joins from the left and there is a petrol station just before
the dual carriageway ends. After passing the small town of Lom Kao the road is
mainly single carriageway with a lot of agricultural traffic.  About 10km north
of Lom Kao a turning on the right is a quiet 'short cut' to the H2216 which goes
to Tham Yai Nam Nao.  However, as this turning is hard to differentiate from the
other junctions it is probably best to keep on the H201 to where it becomes a
dual carraigeway again.  Here there is a large junction with the road becoming
very wide. 

 

At this large
junction the H2216 is on the right and Tham Yai Nam Nao is signposted. There are
several stores at this junction including a shop selling snacks, beer and whisky
and a hardware store that sells 12v 'caving' lamps, digging implements, bailer
twine and wellington boots. About 5km along the H2216 there is a petrol station
and this is the last proper petrol station before Tham Yai Nam Nao.  However,
there are a couple of 'barrel and pump' petrol vendors in the villages along the
road.  These villages also have the usual noodle stalls and small general shops.

 

Although some
maps show a route from the H2010 near Lom Sak going almost directly to the Tham
Yai Nam Nao area this road is still a dirt track that is very rough in places
and takes nearly three times longer to drive compared to going via the H2216.

 

As you enter
the village of Ban Non Chat from the Lom Sak direction the road to Tham Yai Nam
Nao is on the right.  It is signposted and has a yellow, concrete filled, oil
drum in the centre of the junction.  Opposite this junction there is a basic
restaurant selling noodle and rice dishes, beer, etc. that we have frequently
patronised after our caving trips.  On the other side of the road, beside the
junction, there is another noodle shop.  At Tham Yai Nam Nao there is a car
parking area and the ranger station.  The accommodation here is very basic and
the rangers do not have any spare rooms.  There is a camping area down beside
the stream, but apart from the toilets there are no facilities here.  During
busy holiday times there are a couple of stalls selling basic food dishes and
drinks. At other times there is nothing at the ranger station.  However, the
rangers have frequently invited us to join them for aprés-caving drinks and
food.  In return they are happy to receive a box of Chang beer or bottle of
whisky.

 

History of Exploration

 

As is usual
in Thailand the large, dry caves in the National Park have been known to the
local inhabitants since the clearance and settlement of the area.  The caves
have been used as shelters while on hunting trips in the forest, the guano is
mined for use as fertiliser or as a source of saltpeter for making gunpowder and
bats would have been hunted within the caves.  Tham Yai Nam Nao has a large
Buddhist shrine near the entrance and several of the caves in the park have
been, and still are, used by wandering 'thudong' meditation monks.  Monks still
frequently camp at Tham Nop Pa Krauw and use Tham Phaya Naak for walking and
sitting meditation.  The report of the 1992 expedition records that monks were
living at the entrance to Tham Yai Nam Nao, but by 2003 they had moved out. As
part of their meditation practices and due to natural curiosity the monks would
have explored many of the caves and evidence was found which showed that they
had reached the end of the 1992 Series in Tham Yai Nam Nao. The table belows
shows how many of the caves had been visited and explored before our
expeditions. Caving aids include bamboo ladders, bridges and poles used to help
explore the caves.

 

 

 

Prior to the
Shepton Mallet Caving Club's first visit in December 2003 there had been one
recorded visit by cavers to the Nam Nao National Park.  This was by a group of
six British students from Sheffield and Manchester Universities in April 1992. 
They had explored Tham Yai Nam Nao, Tham Pha Rai, Tham Phaya Naak and several
other caves. However, their unpublished report did not give any detailed
location descriptions or grid references. This was because they did not have
detailed maps and were led into the jungle by guides.  After our visit in April
2004 we contacted Nick Standing who was on this 1992 expedition.  Nick supplied
further unpublished information and some photographs which were very helpful in
deciphering the 1992 report.

 

On the first
Shepton Mallet Caving Club Thailand expedition in February 2000 we had stayed at
the Nattirat Grand Hotel in Lom Sak on our way to Khon San in Chaiyaphum
province.  The first cave we ever explored in Thailand was Tham Par Hong in Nam
Nao National Park just off the H12.  On this first expedition we visited caves
in Pha Phueng Wildlife Sanctuary and Phu Pha Man National Park, but didn't
explore any more caves in Nam Nao National Park.

 

Tham Yai Nam
Nao attracted our attention in 2003.  Thorough research did not reveal any
speleological investigations since the 1992 British expedition apart from a
paper in 2001 by Fontaine and Salyapongse which mentioned geological research on
the limestones found on Khao Tham Yai. The basic information on Tham Yai Nam Nao
in 'The Caves of Thailand' was intriguing and we sensed that there could be a
lot more cave in this area.  At the very least we intended to obtain accurate
location data for the caves and if possible to resurvey the caves.

 

The first
visit was from 27 December 2003 to 12 January 2004.  Although we went straight
to ThamYai Nam Nao our explorations were stopped by high carbon dioxide levels
just past the show cave.  We then focused our attentions on the western edge of
the Park.  Several walks resulted in us finding and exploring Tham Pha Rai, Tham
Pha Hok, Tham Pha Pai, Tham Pak Now and various small caves.  By hiring a couple
of rangers we were guided to Tham Song Hong and Tham Pha Ruag. Four days before
the end of the expedition a return to Tham Yai Nam Nao revealed that the carbon
dioxide level had dropped enough for us to access the rest of the cave.  In the
last three trips we surveyed Tham Yai Nam Nao as far as the 'Y Junction' and the
2004 Series was explored to the upstream sump adding an estimated 2.5km to the
length of the cave.

 

This
expedition proved the potential of the Tham Yai Nam Nao area so it wasn't long
before we were back and on 7 April 2004 two cavers were in Lom Sak.  Between 8
and 17 April the survey in Tham Yai Nam Nao was extended to 700m up the 2004
Series and the 1992 Series was explored to the ducks beyond the Boulder Chamber,
rangers guided us to Tham Monhwa and some surface exploration was carried out.

 

The next
major expedition was between 27 December 2004 and 27 January 2005 and a lot of
work was carried out.  In Tham Yai Nam Nao the link to Tham Pha Rai was made,
the survey of the 2004 Series was completed, the end of the 1992 Series was
extended below the large gour to a chamber and the 1992 Series Inlet was pushed
to a small entrance.  To the south of Tham Yai Nam Nao the complex of caves
which includes Tham Bah Dahn, Tham Nop Pa Krauw, Tham Mi Mahn Mek and Tham Phaya
Naak were explored and surveyed.  In addition Tham Monhwa was surveyed and there
were numerous surface walks which discovered various stream sinks and small
caves.

 

During the
rainy season there was a solo trip to the Tham Yai Nam Nao streamway on 5 July
2005 to check on the water level.  The stream was of a similar size to that
observed in January despite recent thunderstorms.  However, this was early in
the rainy season and a visit in September or October would be needed to observe
what would most likely be an impressive amount of water resurging from the cave.

 

The third
expedition was in the Nam Nao National Park from 28 December 2005 to 5 January
2006.  Unfortunately high carbon dioxide levels prevented access to Tham Yai Nam
Nao beyond the show cave.  Despite this set back the Tham Phaya Naak system was
linked together via a series of pitches, Cave 14 was connected to Tham Yai Nam
Nao and two stream caves were found, but not explored.

 

 

Access

 

To explore
caves in national parks in Thailand you should have permission from the Royal
Forest Department in Bangkok.  When in the national parks it is illegal to
collect specimens (including geological specimens) without specific permission
and a full report and surveys should be sent to the Royal Forest Department and
the national park headquarters as soon as possible after your visit. However,
when in the field we have found that the local rangers have not asked for any
written permits and have been very helpful.

 

We entered
the Nam Nao National Park from four car parking places on the northern edge of
the park.  The easiest starting point to find is the car park at Tham Yai Nam
Nao.  The cave is well signposted, both from the H201 (Lom Sak – Loei road) onto
the H2216 and from the other end at the junction between the H12 (Lom Sak –
Chumphae road) and the H2216.  The turning to Tham Yai Nam Nao is about 60km
from either end of the H2216 and is signposted.  From the H2216 road, by
following the only surfaced road through the village of Ban Huai Lat, you soon
reach the ranger station complete with picnic tables, toilets, etc.  From here
Tham Yai Nam Nao and Tham Yai Nam Nao Resurgence are a short walk away.  We also
walked from here to Tham Pha Ruag, Tham Song Hong and Tham Monhwa.

 

The second
parking spot we used was halfway along a rough dirt track to the left (east) of
the surfaced road.  This track turns off about 200m before the Tham Yai Nam Nao
car park and has a large green sign at the start.  This car parking place is the
most convenient one for the path to Tham Song Hong and Tham Monhwa.  The third
car park is at the end of the track, turning right at the only junction to end
up at an irrigated field which often has a crop of cabbages, hence our nick-name
of ‘cabbage patch car park’.  From here a couple of good paths lead southwards
into the forest.  This was the starting point for all the long walks into the
jungle, the Tham Phaya Naak area and for Tham Pha Rai which is about 20 minutes
walk away.  It is also possible to walk to Tham Song Hong and Tham Monhwa from
here via Tham Pha Hok.

 

The parking
place for Tham Pak Now is reached by taking the unsurfaced track to the right at
the T-junction in Ban Huai Lat, turning left in the village to cross the
concrete bridge and then follow the track through the fields.  The track skirts
the western edge of the limestone hills and ends after about 1.5km.  It is then
necessary to walk southwards into the forest along a good path which follows the
stream.  By following the path past Tham Pak Now and ascending the hills to the
east you reach the dolines with the 1992 Inlet entrance to Tham Yai Nam Nao and
the 1992 Sink.

 

To get to
Cave 1 and Cave 2 you need to turn left at the T-junction in Ban Huai Lat and
then go straight on along a dirt track when the sealed road turns right towards
Tham Yai Nam Nao. This dirt track is followed through the fields and over the
rolling sandy hills towards the obvious limestone outcrops.  The car was parked
at the closest point to the cliff.

 

Tham Par Hong and Cave 12 are in the
central part of the national park.  They are very easy to find as there is a
well signed car park on the H12 and a good track can be followed for the 200m to
the cave.

 

Topography of the Tham Yai Nam Nao
Area

 

We are fortunate in that we have
1:50,000 maps which cover the Tham Yai Nam Nao area, both the American Military
series from 1969 and the Royal Thai Survey Department series from 1992.
Unfortunately these 1:50,000 maps do not name many of the topographical features
so we have had to give some of them our own nick-names.

 

There are seven large dolines in
the area. In the list below the number is the lowest altitude in the doline as
marked on the 1:50,000 map.

 

Doline 715 – The doline behind
the cliff with the entrance to Tham Yai Nam Nao.

Doline 735a – 'Banana' doline.
This is the doline with Tham Pha Rai.

Doline 735b – 'Elephant' doline.
Tham Bah Dahn and Cave 25 are in this doline.

Doline 728 – This is a very
large doline which curves around the hill with Tham Phaya Naak.

Doline 806 – The doline below
Cave 11.

Doline 748 – 1992 Inlet entrance
doline.

Doline 771 – 1992 Series sink
doline.

 

The limestone forms only one
massif in which the seven dolines are formed.  This massif has several peaks
with the highest point being the 955m high Khao Tham Yai.  'Banana' and
'Elephant' Dolines and Doline 728 form the eastern edge of the massif with the
eastern boundary of there dolines being sandstone hills.  The other dolines
appear to be formed within the limestone. 

 

Between the dolines there are a
series of steep sided ridges.  The only ridge that has been explored anywhere
near completely is that running south-east from above Tham Yai Nam Nao to the
Tham Phaya Naak area and which marks the eastern edge of the massif.  A few high
level caves have been found near the top of this ridge such as Tham Pha Ruag,
Tham Song Hong and Tham Pha Pai.  This 'Tham Pha Pai' ridge ascends to a summit
and then splits with one ridge running south-west towards Khao Tham Yai and Tham
Monhwa as well as continuing south-east.

 

The presence of dry stream beds
which meander through the surrounding fields indicate that in the wet season
several streams resurge along the north edge of the limestone massif. However,
we have found only two perennial streams flowing north out of the limestone
massif which are the Tham Yai Nam Nao resurgence and the stream which flows
north past Tham Pak Now on the western edge of the hills.

 

Although not shown on the
1:50,000 maps there are seasonal and perennial streams sinking in all seven of
the dolines.  The only perennial streams are those which flow off the high
sandstone hills to the east of the park into 'Banana' and 'Elephant' dolines and
Doline 728.  The streams sinking in the other dolines flow over limestone and
have either no flow or very low flow in the dry season.

 

The Caves

 

Tham Yai
Nam Nao System

 

Tham Yai
Nam Nao
ถ้ำใหญ่น้ ำหนาว

Tourist
entrance: 47Q 0767316 1874832  Alt.: 693m

Second entrance:
47Q 0767329 1874822 Alt.: 711m

Bat entrance:
47Q 0767332 1874774                   Alt.: 729m

Cave 14
entrance: 47Q 0767954 1873736 Alt.: 740m

1992 Inlet
entrance: 47Q 0767459 1872603          Alt.: 750m

Tham Pha Rai 
ถ้ำป่ใร่

Stream entrance:
47Q 0768798 1874006  Alt.: 730m

Upper entrance:
47Q 0768805 1874000                Alt.: 738m

Other names: Wet
Sink [1992 expedition]

 

Length:
9,817m (800m unsurveyed)  VR: 76m

 

This is the longest cave that has
been found in the National Park and is now the third longest known cave in
Thailand.  It is a popular tourist attraction and is clearly signposted from the
H2216 in Ban Non Chat.  At busy holiday times there are stalls selling food and
beer, but at other times there are just three or four rangers who are there to
guide tourists into the cave.  The charge is 20 baht for a tour.  To just have
the lights turned on for an unguided tour costs 10 baht. These rangers are also
willing, for a suitable fee, to guide you to other nearby caves. We have paid
200 baht per man for guiding and have also donated boxes of Chang beer to the
ranger station.  In return we have been encouraged to explore the caves and
occasionally invited to join the rangers for post-caving drinks and food.  The
rangers have been very interested in our explorations.

 

From the car
park the path descends to and then crosses the stream which resurges from the
cave.  The path then ascends to a shrine (note the cloth 'tungs' hanging from
the cliff and the fortune telling sticks) and then up metal stairs to the
'Tourist' entrance.

 

Inside the
cave a metal ladder and walkway soon leads to the 'Second' entrance.  By exiting
the cave via this entrance it is possible to ascend the cliff past an unexplored
cave entrance (which almost certainly links back into the main cave) and up to
the 'Bat' entrance. Beyond the Second entrance the subtly lit 'Tourist Cave'
follows a large fossil passage.  There is a bat colony in the big chamber where
the 'Bat' entrance enters from high on the right. Beyond the bat chamber the
cave has a few formations and then reaches a breakdown area with a series of
high level passages ascending up on the right.  This area has not been fully
explored or surveyed (there is perhaps 100m of passage up here), but daylight
has been seen high up above a climb and a strong, cool draught comes down into
the cave from up here.  After the breakdown area there is a mud floored chamber
that funnels down to the left.  By descending this it is possible to go through
a low, squalid, occasionally wet section to reach the bottom of the 6m ladder. 
However, it is easier to follow the lit cave which ends at the top of the
solidly constructed 6m metal ladder.  Descending the ladder leads to a series of
smaller, muddy passages.  The main way on, marked with white paint arrows, is a
short crawl on the right followed by some smaller passages with a second crawl. 
Finally there is a flat out crawl of about 10m over mud which breaks out into a
large passage with a mud and silt floor.

 

This large
passage ends by descending a mud slope to a stooping and crawling height
passage.  This area occasionally has a pool of water and can be prone to carbon
dioxide build up – we recorded over 5% here on our first visit and this section
was impassable. In January 2006 this section again had a pool of water and very
high carbon dioxide levels making the rest of the cave inaccessible.  However,
once past this low section you regain the large passage, named 'Main Passage' by
the 1992 expedition, which meanders gently to the junction with the streamway. 
The passage is floored with sand and dry mud which has created some large
mudbanks.

 

At the
streamway it is possible to climb down the 3m bank of cobbles and mud fill. It
is also possible to reach the stream via the network of small passages on the
left just before the climb.  Downstream enters a small passage with many
cascades and deep pools, a couple of which can require swimming to cross in high
water conditions, to end at a sump.  Upstream is a magnificently large streamway
with a lot of cemented cobble fill on the walls and floor.  After 275m the
passage makes a 90°
turn to the south.  The passage changes character as the gradient is lower and
more wading is required, often at stooping height.  It is possible to bypass one
particularly low and wet section by taking a high level route on the left hand
side.

 

Before
reaching this high level bypass there is a small, insignificant inlet on the
left hand (eastern) wall of the passage.  This starts as a flat out crawl over
cobbles to a small chamber.  More crawling leads to a stream which disappears
into a very small hole in the left hand wall.  The stream way continues as
mostly crawling for a total of 300m to a wide pool with very limited airspace. 
A gravel bank was dug out and the water level lowered.  Crawling through the
duck for 50m leads into a high rift passage which is the end of Tham Pha Rai. 
This cave is described after the Tham Yai Nam Nao description.

 

After the
Tham Pha Rai inlet and high level passage you reach the 'Y Junction'.  The main
stream comes in from under the left (eastern) wall and can be difficult to spot
– it wasn't found by the 1992 expedition and the 2003 expedition walked past it
twice before finding the duck under into the streamway.  This junction is
clearly marked with a painted 'Y'.

 

This
streamway, named the '2004 Series', was first explored by the Shepton Mallet
Caving Club in January 2004. At the 'Y Junction' a short, wet crawl leads
into larger passage where there is a short section of wading in deep water. The
stream meanders across the floor of a fairly straight passage and there are
extensive deposits of sand and mud. After 450m from the junction the roof lowers
and more wading is required. The water gets steadily deeper until at 700m from
the junction you are in water over 1.5m deep with only 20cm of airspace. The
water soon gets shallower, but the low, wet crawling continues for another 200m
until you reach larger passage and can stand up out of the water. This series of
wet crawls ends in a very high rift passage. The passage is now easy going for
about 400m to a dry oxbow on the left which is followed for 100m back to the
streamway.  After the  oxbow the streamway continues for about 1.5km to the
upstream sump and no side passages or inlets have been found (only two groups
have been to the sump).  The going is mainly wading with varying water depths
and one short swim.  In one section just before the sump the passage is up to
20m wide and 45m high and there are a couple of places where it is necessary to
scramble over a boulder floor with the stream flowing below. Large numbers of
medium sized bats have been seen in a couple of places in the 2004 Series
suggesting that there are other entrances into this section of the cave.

 

The 2004
Series heads in a south-easterly direction and is a fairly straight passage with
few meanders.  This trend follows the alignment of ridge of the mountain above
the cave and is following the strike of the limestone's bedding.  The upstream
sump is 300m from the stream in Cave 25 and the downstream sump in Tham Bah
Dahn.

 

From the 'Y
Junction' the other branch of the cave leads southwards and has been named the
'1992 Series' as it was first explored by the student expedition.  In the dry
season it does not have a stream for most of its length until you reach the
'Boulder Chamber'. After about 200m it is necessary to crawl through a low,
muddy, sometimes wet, passage for about 100m.  Above this section there is a
series of dry, boulder-filled chambers. Cave 14 was connected to Tham Yai Nam
Nao just before this crawling section and is described below.  After the crawl
the large passage is regained and it is mainly easy going for 500m to the
'Boulder Chamber' with just some crawls under boulders and flowstone to
negotiate.  About 100m before reaching the Boulder Chamber there is a small
series of side passages that has been used as a campsite by previous explorers,
probably monks.

 

The Boulder
Chamber is the second largest chamber in the cave (after the Bat Chamber in the
Tourist Cave) and is a collapse feature on the left (eastern) side of the stream
passage.  It is possible, with great care, to ascend the slope of boulders and
debris to reach the back wall of the chamber, but the rock is heavily corroded
and friable.  There didn't appear to be a passage entering into the roof of the
chamber. There might have been a high level passage heading downstream, but
access would have been via a very exposed traverse.

 

After the
Boulder Chamber the stream passage becomes smaller and passes through a couple
of small, decorated chambers.  Eventually you reach a duck.  This duck, and the
three following ducks, are easily passed and the large main passage is rejoined.
This 200m of passage is quickly traversed to end at a large gour that fills the
passage.

 

About 50m
before the gour there is a tall, vadose inlet passage on the right (western)
side, named the '1992 Series Inlet'. The inlet passage is followed for about
400m to a boulder choke. The stream is regained beyond the choke and can be
followed upstream to a 5m climb up a waterfall. This is free climbable, but a
handline is advised. The water is then followed to a second boulder choke. The
path of least resistance leads to a duck which may need bailing. Beyond the duck
a crawl of 10m goes straight on and then sharp left to a squeeze. After the
squeeze a slot up to the left leads to the surface. However, only the thinnest
member of the expedition was able to pass through the slot.  Above the first
boulder choke there is a chamber where evidence of a camp and bats was found. 
Noodle packets were found at this camp which had a sell by date of 2530 BE (1987
AD), which is five years before the student expedition in 1992!

 

The 1992
expedition had failed to pass the large gour that blocks the main stream passage
in the 1992 Series. They had looked for a route over the top and had pushed the
wet crawl underneath for about 2m.  In January 2005 concerted canal digging
lowered the water level by 20cm.  A wet crawl lead to the left while the stream
came in from the right. Continuing to the left went through a flat out crawl in
a pool. Beyond the pool a small chamber was reached.  The way on was to crawl
through another pool and head right to a dry crawl.  Finally bearing left and
following the crawl over cobbles allowed the very large passage to be regained. 
By ascending the boulder floored passage a pool is reached at the base of a 10m
aven. The stream enters at the top of this aven which has not been climbed and
is currently the end of exploration in this section of the cave.

 

Cave 14 was
found on a walk from Tham Yai Nam Nao via the very steep path which goes to Tham
Pha Ruag.  From this col access was gained to the bottom of Doline 715 and when
ascending back out of this doline towards Tham Song Hong the 20m deep entrance
shaft was found.  The entrance is the sink for a seasonal stream.  The shaft was
descended in January 2006 and linked to the 1992 series by 80m of muddy crawls.

 

Tham Pha Rai
is an active swallet and was known as Wet Sink to the 1992 expedition. The
entrance is located in the first doline, 'Banana' doline, to the south-east of
the 'cabbage patch' parking place.  After descending into the doline the path
flattens out as it goes through an old banana plantation.  After about 100m the
stream channel is 30m to your right.  If you can't find the stream keep
following the path as this soon crosses the stream which can then be followed
down to the cave.

 

There are two
entrances, but there is little point scrambling up to the dry entrance as you
will soon get wet inside the cave.  Going in the wet entrance and across a 0.5m
deep pool brings you to a 7m pitch.  At the bottom of this the stream descends a
couple of short drops and after crossing a pool a crawl leads to the main
streamway.  Upstream the passage can be followed for 100m through a couple of
ducks to a sump.  Downstream the cave goes for about 500m through varied
passage.  In places the passage is large and triangular in cross-section where
it has formed along the strike.  In other places it is necessary to crawl under
flowstone blockages.  Eventually the stream disappears into a low passage and
then sumps.  Just before the stream enters the low section there is a small hole
on the right which leads up into a boulder choke above the sump. A route through
the boulder choke was found (it has been marked with string!) which leads back
to the stream.  This stream passage is generally small and it is often necessary
to crawl round low sections, over boulders, wade a short canal, etc. to
eventually reach the high inclined rift passage which has already been described
from the Tham Yai Nam Nao end.  The through trip from Tham Pha Rai to Tham Yai
Nam Nao is recommended.

 

Although the
two upstream ends of Tham Yai Nam Nao have been found there is still potential
to extend the system.  The Shepton Mallet Caving Club survey currently ends at
the first duck upstream of the Boulder Chamber so the 1992 Series Inlet and
extension beyond the gour have not been surveyed (and have only been visited
once).  Other possible extensions are by diving the resurgence or downstream
sumps; high level entrances to the Tourist cave, Tham Pha Rai Inlet, the 1992
Series or 2004 Series; various oxbows and unclimbed avens; joining the Cave
25/Tham Bah Dahn/Tham Phaya Naak area caves to upstream 2004 Series which would
add over 2km to the length; linking caves high on the mountain above, such as
Tham Monhwa where exploration of a shaft system was stopped due to high carbon
dioxide. 

 

Tham Yai
Nam Nao Resurgence 

Main entrance:
47Q 0767346 1874950                 Alt.: 676m

Upper entrance:
47Q 0767360 1874943                Alt.: 690m

Length:
130m                            VR: 11m

 

The stream
resurges from amongst boulders on the left hand side of the path to Tham Yai Nam
Nao.  A 1.5m high entrance to the right allows dry access into the streamway
which can be followed for a few metres, past a small second entrance on the
right and across a pool to reach the base of a rift.  This rift is a third
entrance, but the steeply sloping rubble bank is tricky to descend.  Beyond this
rift entrance the water can be followed along 80m of canal (up to 1.2m deep) to
reach a deep upstream sump.  White fish were seen in the sump pool and if they
are found to be cave adapted they are most probably a new species as no other
cave fish are known from this hydrological basin.

 

A dive at the
upstream sump has plenty of potential to reach several hundred metres of air
filled passage.  The sump is formed by a steeply dipping chert bed in the roof
and thus it is likely to be a short sump.

 

Cave 27

Approx. 47Q
0767950 1873900               Alt.: 750m

Length:
~10m                            VR: ~10m

 

From the col
above Cave 14 take the path southwards towards Cave 14.  When you reach a gulley
follow it down for about 200m to the cave.  Cave 27 is a seasonal stream sink in
a limestone outcrop.  The entrance pitch is estimated to be 10m and has not been
descended.

 

1992 Series Sink

47Q 0767786
1872218                Alt.: 770m

Length:
~3m                              VR: ~3m

 

Walking via
Tham Pak Now a large stream sink was found at the bottom of Doline 771, but was
not investigated properly because of a lack of kit.  The stream sinks into
boulders and can be seen to descend 3m and then go 3m horizontally.  The sink is
approximately 150m south of the aven at the end of the 1992 Series in Tham Yai
Nam Nao.

 

High Level Fossil Caves

 

Cave 13

47Q 0767727
1874364                Alt.: 810m

 

This entrance
was found when ascending from the bottom of Doline 715 towards Tham Pha Pai. 
The hole will need digging, but was draughting out in January 2005.

 

Tham Pha
Ruag 
ถ้ำป่รวก

47Q 0767936
1874604                Alt.: 860m

Length:
59m                              VR: 11m

 

Tham Pha Ruag
is a very short remnant of a high level fossil system.  The cave is located to
the east of the col above Tham Yai Nam Nao and is reached by a very steep path
up the side of the hill just to the east of the ranger station. From the Tham
Yai Nam Nao car park walk down the surfaced road for a few metres and then
follow the first track on the right (east) which leads to some fields.  The path
heads north into the forest about 100m past a bamboo shack, but is difficult to
find.  Alternatively it is possible to reach this area via the path that goes to
Tham Song Hong and then ascend to the ridge and head north.

 

The entrance
is a small hole about 1.5m in diameter and opens onto a 4m pitch. This was
already "rigged" with a bamboo pole, but we installed our own lifeline (belayed
to a fresh bamboo pole over the entrance).  The pitch drops into a small chamber
with some formations and a passage on the left leads to a smaller second
chamber.

 

Cave 18

47Q 0768009
1874348                Alt.: 830m

Length:
~5m                              VR: ~2m

 

From Tham
Song Hong the ridge was followed north towards Tham Pha Ruag.  At the base of
the summit outcrop, on the eastern side, there is an inclined area of exposed
limestone.

 

A 5m long
vadose canyon was found near the southern edge of the exposed limestone. Much of
the canyon is unroofed and there are numerous other holes in this area.

 

Tham Song
Hong 
ถ้ำสองห้อง

Lower entrance:
47Q 0768150 1874261                Alt.: 820m

Upper entrance:
47Q 0768183 1874172                Alt.: 836m

Length:
215m                            VR: 23m

 

This is a
large, truncated fossil cave on the limestone ridge above Tham Pha Rai.  The
cave can be reached from either the Tham Yai Nam Nao car park or from the
'cabbage patch' car park. The cave has been used as a retreat by monks.

 

The wide
lower entrance opens into a big fossil passage with many large formations.  A
route between the formations climbs up to a ledge where there is a short passage
off to the right.  To the left the passage closes down for a short distance
before opening up again.  The smaller upper entrance is soon reached.  Another
smaller passage leads steeply down from the upper entrance.  This appears to
take a small stream in the wet season, but is solidly choked with mud. 

 

Tham Pha
Pai 
ถ้ำป่ใผ่

47Q 0768307
1874020                Alt.: 860m

Length:
84m                              VR: 7m

 

This is
another remnant of the old high level system.  It is located only a few metres
below the ridgeline between Doline 715 and 'Banana' doline on the eastern side
of the mountain.  From the 'cabbage patch' car park take the path up the valley
to the col where the main path goes to the left towards Tham Pha Rai and Tham
Phaya Naak. Take the path which turns off to the right, past Tham Pha Hok, and
ascends towards the ridge.  The cave is to the right of the path and is not
particularly obvious despite the large entrance.  Alternatively go past Tham
Song Hong and follow the ridge south.  However, the path goes over the top of
the cave and the entrance cannot be seen.

 

The entrance
has been used as a retreat by monks.  To the right a small passage soon closes
down. To the left the passage leads to a second chamber which has been mined for
guano.  At the back of the chamber the passage is completely choked with clastic
fill and a small oxbow in this fill has been crawled through.

 

Tham Pha
Hok 
ถ้ำป่หก

Main
entrance: 47Q 0768482 1874257                 Alt.: 760m

Second
entrance: 47Q 0768495 1874248 Alt.: 759m

Pitch
entrance: 47Q 0768465 1874257                 Alt.: 770m

Length:
51m                              VR: 13m

 

Tham Pha Hok
is a short fossil cave located above a flood sink at the northern end of the
'Banana' doline.  It is in a cliff only a few metres uphill and to the right
from the first col reached from the 'cabbage patch' car park.  The cave has four
entrances, one of which is small and another is a 7m pitch.

 

Cave 7

47Q 0768404
1874234                Alt.: 780m

Length:
~20m                            VR: ~5m

 

Just beyond
Tham Pha Hok there is an outcrop of limestone on the right of the path.  The
cave in this outcrop has a couple of entrances rigged with old bamboo ladders,
but the cave has not yet been surveyed and this area needs to be looked at more
closely.

 

Cave 8

47Q 0768408
1874263                Alt.: 770m

Length:
~10m                            VR: ~5m

 

A few metres
downhill from Cave 7, but further away from the path, Cave 8 is a short phreatic
tube descending at a 45° angle.

 

Draughting
holes amongst boulders

47Q 0768453
1874218                Alt.: 775m

 

Opposite Cave
7, on the left of the path and a few metres uphill from Tham Pha Hok, there is a
limestone outcrop and a jumble of boulders.  A draught has been detected blowing
out from between these boulders.

 

This area
with Tham Pha Hok, Cave 7, Cave 8 and the draughting holes is of interest as it
is above the Tham Pha Rai Inlet in Tham Yai Nam Nao.

 

Cave 15

47Q 0768372
1873545                Alt.: 820m

This cave is
located on the side of Doline 715 as you descend from the path which follows the
ridge between Tham Pha Pai and Tham Monhwa. This hole will need digging, but was
draughting out in January 2005.

 

Tham
Monhwa 
ถ้ำมอนว้า

Main
entrance: 47Q 0768555 1873314                 Alt.: 952m

Second
entrance: 47Q 0768529 1873376 Alt.: 947m

Length:
365m                VR: 55m

Other names:
Tree Forest Cave [1992 expedition]

 

Tham Monhwa
is in an interesting location high on Khao Tham Yai.  The easiest access is the
path via Tham Song Hong.  Follow this path south-east, past Tham Pha Pai to the
limestone outcrops at the top of the hill.  The path then bears left and
descends and contours round the southern edge of Doline 715.  The path then
ascends passing Cave 21 and Cave 22.  The Second entrance is a few metres above
the path before you reach these two shafts, but can be hard to find.  The main
entrance is on the other side of this hill and is best reached by contouring
round to the left.

 

The main
entrance to Tham Monhwa is a spectacular, large collapsed passage.  To the right
(east) a short passage crosses a bamboo bridge to a 5m pitch down into a large
passage.  This passage ends at a slippery climb up (which wasn’t ascended) with
an aven above which was draughting inwards.  On the left hand side (west) of the
main entrance there is a series of pitches, but unfortunately high carbon
dioxide levels (a cigarette lighter wouldn’t work) stopped exploration.  The way
on down another pitch could be seen.

 

The 1992
expedition reported another cave, Miserly Spirit Cave, with a large entrance
close to Tham Monhwa, but this has not been found.

 

Cave 21

47Q 0768481
1873364                Alt.: 948m

Length:
~20m                            VR: ~15m

 

The path to
Tham Monhwa ascends a limestone outcrop and two shafts are found beside the
path, just past the second entrance to Tham Monhwa.  Cave 21 is a 15 m pitch
into a blind rift heading towards the nearby Cave 22.

 

Cave 22

47Q 0768490
1873372                Alt.: 931 m

 

This shaft is
located close to and on the same joint as Cave 21. It has not been descended,
but is almost certainly another blind shaft.

 

Cave 11

47Q 0768765
1873158                Alt: 922m

Length:
45m                              VR: 18m

Other names:
Cliff Cut Path Cave [1992 expedition]

 

While
crossing the flat floor of 'Banana' doline, after crossing the stream which
sinks at Tham Pha Rai, the path forks.  Left leads up to the far end of the
doline and on to Tham Phaya Naak.  However, the right hand fork ascends the
steep side of the doline to a col between 'Banana' doline and Doline 806. The
easiest path goes right (north) and ascends a ridge before heading left and
decsending gently around the northern side of the doline (for a short distance
it appears to follow an old track cut into the side of the hill).  A limestone
outcrop is seen above the path and the entrance is at the base of this outcrop.

 

The 12m
entrance shaft lands in a chamber 10m by 10m with a blind rift at one end and no
way on.  The cave is located a couple of hundred metres to the south-east of the
end of Tham Monhwa.  The 1992 expedition report described Cliff Cut Path Cave as
being "on the side of a rocky knoll, a small entrance leads to a 10m by 10m
chamber containing weathered calcite.  An 8m pitch was descended to another
chamber with a pool, and no obvious way on."  This description is close
enough to what we saw in Cave 11 to be confident they are the same cave.

 

The ridge to
the north-east of Cave 11 has been descended from Tham Monhwa to the col down to
'Banana' doline (not recommended as it is steep and overgrown with no paths). 
However, the rest of this doline has not been explored.

 

Tham Phaya Naak Area

 

These caves
are a brisk 1½ hour's walk from the 'cabbage patch' parking area.  Follow the
path up the valley to where the path to Tham Pha Hok, Tham Song Hong and Tham
Monhwa forks off to the right.  Take the track left, over the crest and descend
into the 'Banana' plantation.  After passing Tham Pha Rai the path crosses the
flat floor of the doline through an old banana plantation.  It then ascends
steeply to a col at the south-eastern end of the doline.  The path contours
round to the right and crosses a gully (this gully has been descended into the
'Elephant' doline, but this route can be best described as hard) before gently
ascending to a second col.  The path than narrows and traverses round to the
right, going across the steep mountainside.  This path is also used by
elephants.  The far end of the traverse is marked by a limestone outcrop and the
path descends.  Head left and go round the left hand side of the limestone
hill.  At the next col you can either follow a path right which descends to Cave
5 or take the path that goes left and then ascends round to the right to Tham
Nop Pa Krauw.  At Tham Nop Pa Krauw there is a camp used by forest monks and the
southern entrance to Tham Phaya Naak is reached by continuing along for about
50m and then dropping down by about 30m in altitude.  A path from Tham Nop Pa
Krauw heads up the hill to Tham Wi Mahn Mek.

 

Tham Phaya
Naak, Tham Wi Mahn Mek and Tham Nop Pa Krauw have been connected via a large
pitch. This connection has created a system which is 1.2 km long and 133 m
deep.  The 650m long Tham Bah Dahn, near the bottom of Doline 725 ('Elephant'
doline), runs below the Tham Phaya Naak system.  There is a tall rift passage in
Tham Bah Dahn below the shaft that links up the Tham Phaya Naak system.  Cave 25
is downstream of Tham Bah Dahn and has an open streamway that has not yet been
explored.

 

Tham Phaya Naak System

Tham Wi Mahn Mek


ถ้ำวิมานเมฃ

Main
entrance: 47Q 0769746 1872034                 Alt: 875m

Eastern
entrance: 47Q 0769819 1872059 Alt.: 874m

Tham Nop Pa Krauw 
ถ้ำนพเก้า

47Q 0769664
1872010                                        Alt.: 848m

Tham Phaya Naak
 ถ้ำพญานาึค

North
entrance: 47Q 0769838 1872159                Alt.: 801m

South
entrance: 47Q 0769648 1871890                Alt.: 812m

Other names:
Tham Pa Pha Rai [Caves of Thailand], Bamboo Cave [1992 expedition]

 

Length:
1,285m (80m unsurveyed)           VR: 133m

 

Tham Phaya
Naak had been explored and surveyed by the 1992 expedition.  Their survey showed
a large passage that linked two smaller entrances.  The cave looked impressive
and we had hoped to be able to relocate the cave on our first expedition to Nam
Nao.  We didn’t find it on this first trip although we were very close when
exploring Cave 5 and Tham Nop Pa Krauw.  However, we did manage to find it in
2005 because some forest monks were in residence at Tham Nop Pa Krauw and they
guided us to the southern entrance.

 

Tham Wi Mahn
Mek has one entrance at the base of the limestone outcrop at the top of the
hill.  The main passage of Tham Wi Mahn Mek has several skylights and goes
through the hill to a second entrance. A passage to the right inside the main
entrance leads to a large chamber in the floor of which there is a very large
pitch that has been aurally connected with the pitch in Tham Nop Pa Krauw, but
the pitch has not been descended.  The total depth of this pitch is around 70m.

 

The entrance
to Tham Nop Pa Krauw is located lower down the hill than Tham Wi Mahn Mek.  The
first visit was in January 2004 and exploration was soon stopped by a crawl
after 90m. This crawl was dug out a year later to reach about 40m of passage
ending at a pitch.  This pitch was descended into a big chamber where the
connection to Tham Wi Mahn Mek was above and to the right.  In January 2006 the
pitches linking this cave to Tham Phaya Naak were descended and surveyed.

 

The southern
entrance to Tham Phaya Naak is small, but a very strong draught blows out of the
cave.  A 3m bamboo ladder lands in a narrow passage that gradually gets larger
as you follow it to the north-east. Another 3m bamboo ladder allows access to
the large main passage.  A high level oxbow goes from above this second ladder
round into the main passage.  There is a shrine in front of a large calcite
column and the cave is also used by the monks for walking meditation.  The large
passage descends gently to a junction with a passage on the right.  The right
hand passage soon reaches a T junction and the pitch in from Tham Nop Pa Krauw
lands at the junction. To the left leads steeply up a mud slope to end at the
foot of an aven.  This pitch is stal covered and appears to be about 20m high.
To the right the passage soon ends at a grotto.  A pit in the floor has been
descended for 4m and was found to be blind.  This blind pit is above the high
rift passage in Tham Bah Dahn.  Before the grotto an inclined, mud floored
passage on the right can be followed for about 30m.

 

Back at the
junction the main passage continues, but soon reduces in size.  The monks have
constructed various bamboo ladders and bridges which allow you to ascend through
several small chambers and climb up to the small northern entrance which is in
the other side of the hill to where you went in.  This area near the northern
entrance appears to take a small stream in the wet season.

 

Cave 23

47Q 0769838
1872087                Alt.: 894m

Length: ~10m

 

From the
eastern entrance to Tham Wi Mahn Mek turning left brings you to Cave 23.  It is
a small shelter cave with a couple of beds.

 

Cave 24

47Q 0769858
1872052                Alt.: 875m

Length: ~20m

 

From the
eastern entrance to Tham Wi Mahn Mek turning right brings you to Cave 24.  This
cave is about 20m wide and deep and is also used by monks.  There is a skylight
entrance to the right and the cave has some fossil calcite bosses.

 

Cave 10

47Q 0769673
1871887                Alt.: 825m

Length:
35m                              VR: 2m

 

From the
southern entrance to Tham Phaya Naak a large cave entrance can be seen in the
cliff above.  After climbing the 20m to the entrance the cave is found to
consist of a 10m entrance chamber with a small crawl leading off from the back
of the cave.  The crawl was not draughting in January 2005.

 

Cave 5

47Q 0769664
1871759                Alt.: 776m

Length:
~100m                          VR: ~35m

 

Cave 5 is
located below and about 100m from the southern entrance to Tham Phaya Naak.  Due
to its location and nature (a boulder choke) there was a hope that it might have
connected with the streamway between the stream sink in Doline 728 and the
upstream end of Tham Bah Dahn.

 

The cave had
been found in January 2004, but had not been explored to a conclusion. The small
entrance opens into a chamber.  From here it is possible either to descend the
steep, dry streamway which has a couple of climbs in it or to descend the
chamber to the left.  At the bottom the way on is down through a boulder choke. 
This was looked at by two groups in January 2005, one of which used a ladder to
descend the choke, but due to time constraints a definite conclusion was still
not found.  In January 2006 there were two visits to Cave 5 when more determined
and better equipped explorers pushed down through the boulders until it became
too tight.

 

Tham Bah
Dahn 
ถ้ำบาดาล

47Q 0769885
1872279                Alt.: 760 m

Length: 655
m                           VR: 29 m

 

This stream
cave is located in 'Elephant' doline to the north of Tham Phaya Naak. Although
this is likely to be the stream seen in the 2004 Series of Tham Yai Nam Nao it
runs in a south-west to north-east direction which is at 90°
to the 2004 Series.  It runs below the Tham Phaya Naak system, but no
indications have been seen that the caves are connected.  The streamway appears
to be the link between the stream sinking in Doline 728 below Cave 5 and the
2004 Series streamway.  Cave 25 is between the known ends of Tham Bah Dahn and
the 2004 Series and the stream sinking in 'Elephant' doline probably joins this
cave.

 

The entrance
passage is rigged with rotten bamboo ladders on the drops and leads down to a
streamway that quickly sumps going downstream.  Heading upstream there is a
muddy slope and chamber on the left which ascends to a possible second
entrance.  After the chamber there is over 500m of passage to a sump.  This
stream passage is very high in places.  With a lot of work it might be possible
to dig away the sandbanks at the upstream end and lower the sump.

 

Cave 25

47Q 0769928
1872305                Alt.: 750m

Length:
25m+                            VR: ~5m

 

The entrance
to Cave 25 is, according to the GPS fixes, 50m north-east of Tham Bah Dahn and a
few metres lower.  To enter the cave you climb down an old dry waterfall for
about 10m.  The stream comes in from ahead of you (from Tham Bah Dahn?) into a
clean cut passage heading downwards at about 60°.  It is possible to climb down
the slope for about 5m to where a ladder or handline is required.  Falling water
could be heard at the bottom.

 

The following
two sinks and three caves were originally reached by walking from the 'cabbage
patch' car park along the path that traverses the sandstone hills on the eastern
flanks of the 'Banana' doline and 'Elephant' doline.  These sites are in the
third doline along, Doline 728, but a long way upstream from the bottom of the
doline which is below Cave 5. Easier and quicker access to these sites is to
continue along the path that goes to Tham Phaya Naak, turning left to Sinks 1
and 2 and Caves 19 and 20 or continuing straight on to reach Cave 26.

 

Sink 1

47Q 0770114
1871638                Alt.: 755m

 

This sink was
thought to be the sink for the stream seen in the 2004 Series in Tham Yai Nam
Nao. However, the exploration of Tham Bah Dahn has cast doubt on this
hypothesis. A stream was sinking here in January 2005. The sink is choked with
wood and bamboo which will have to be removed to allow exploration. A rope or
ladder might also be useful to gain entry.

 

Sink 2

47Q 0770233
1871587                Alt.: 755m

 

An overflow
sink for Sink 1 which has a small stream sinking in it.

 

Cave 19

47Q 0770214
1871540                Alt.: 755m

Length:
~2m                                          VR: ~2m

 

There are two
shakeholes at this location.  The larger hole needs kit to descend the 2m deep
drop between boulders. Not explored.

 

Cave 20

47Q 0770062
1871551                Alt.: 755 m

Length:
~5m                                          VR: ~5 m

 

Cave 20
consists of a 5m drop in two steps leading to a crawling sized cave that hasn't
been explored.  There are several other shakeholes in this area.

 

Cave 26

47Q 0770376
1871080                Alt.: 790m

Length:
~65m                            VR: ~2m

 

To reach Cave
26 follow the path beyond Tham Phaya Naak down to the floor of doline on the
right (west).  The two small entrances are in an outcrop next to open area.  The
larger entrance has a camp inside.  Climbing over the bed leads to a fossil
passage with the other entrance immediately on the left.  After 15m a 2m climb
down leads to a further 50m of walking passage to a large static pool which has
a strong draught flowing out and appears to be a duck with water about 0.5m
deep.  However, the cave was not properly explored and has great potential as it
is over 1km from the upstream sump in Tham Bah Dahn.

 

Cave 17

47Q 0771387
1871712                Alt.: 900m

Length: ~10m

 

This cave was
found on the longest walk so far made by the Shepton Mallet Caving Club into the
forests of the Nam Nao National Park.  The good path follows the edge of the
sandstone hills just outside the eastern boundary of the park past the 'Banana'
and 'Elephant' dolines and nearly past Doline 728.

 

This cave is
located in the line of limestone cliffs that are on the eastern edge of the
national park. This is an old relict cave used as a camp by hunters. A bamboo
ladder leads up to the 10m long, 5m wide by 30m high cave.

 

Western Caves

 

Apart from
the 1992 Inlet entrance to Tham Yai Nam Nao and the 1992 Series Sink (which have
been described above) only one cave is known from the limestone hills on the
western edge of the massif.  However, very little exploration work has been done
in this area. 

 

Tham Pak
Now 
ถ้ำพัคเน่า

47Q 0766600
1872899                Alt.: 757m

Length:
75m                              VR: 15m

 

See the
Access section for the car parking spot for Tham Pak Now.  From here take the
path that follows the valley floor until some limestone cliffs are seen on the
right.

 

Tham Pak Now
is a short relict cave with a large chamber about 30m across.  Some small
passages and crawls were not explored. It has been used extensively by monks in
the past. The cave is in a limestone outlier on the western edge of the
mountain. This area needs to be looked at more closely on future expeditions.

 

 

Tham Par Hong Area

 

The caves
here are in an isolated limestone outlier about 20km south of Tham Yai Nam Nao. 
Access is easy via the H12 and Tham Par Hong is signposted from the road.  We
walked south-west round the hill from Tham Par Hong, down into the dry valley
and back up to the road. There does not appear to be any major caves here, but
more limestone outcrops may be present to the north.

 

Tham Par
Hong 
ถ้ำผาหงษ์

Upper entrance:
47Q 0767755 1854078                Alt.: 885m

Small entrance:
47Q 0767755 1854078                Alt.: 878m

Lower
entrance: 47Q 0767755 1854082                Alt.: 879m

Length:
105m                            VR: 11m

 

This cave is
very well known and is sign posted off the H12.  A metal ladder leads up to a
shrine formed in a short bit of passage.  Below this shrine two smaller
entrances lead into a more extensive cave.  To the left a 3m deep rift has been
descended and apart from an oxbow in the western wall was found to be blind. 
The passage to the right was followed to where crawling was necessary.

 

Cave 12

47Q 0767824
1853906                Alt.: 855m

Length: ~10m

 

By following
the base of the limestone hill for about 100m past Tham Par Hong this cave is
reached.  The cave consists of a couple of short phreatic tubes with bamboo
structures built by monks.

 

Caves Outside The National Park

 

Whilst
exploring the eastern edge of the limestone massif a couple of small caves were
found in one of the limestone cliffs.  These limestone cliffs are outside the
park boundaries.

 

The vehicle
access to these caves is described in the Access section.  From the end of the
track head down across the field to the bottom of the small valley and follow
the path up through the forest to the large main entrance to Cave 1.  To reach
Cave 2 continue to follow the path up the stream bed, past the upper entrance to
Cave 1 and then continue round to the other side of the limestone cliff.

 

Cave 1

Main entrance:
47Q 0769310 1875793                 Alt.: 830m

Upper entrance:
47Q 0769357 1875767                Alt.: 841m

Length: 90m
                             VR: 14m

 

The large
main entrance, which is 15m wide by 5m high, appears to be considerably older
than the small seasonal stream passage which leads to the upper entrance.  This
main entrance is heavily choked with calcite and clastic deposits. and is used
occasionally by monks.  The streamway is only 1m to 1.5m high and about 1m
wide.  After 70m the cave opens out into a small chamber.  The upper entrance
enters the far end of this chamber as a rift and has a small climb.  There is a
possible high level passage leading off from this chamber.  There are a couple
of bamboo poles which have been brought into the cave to enable one to reach the
top of the chamber, but we didn’t attempt the ascent.

 

Cave 2

47Q 0769402
1875587                Alt.: 860m

Length:
43m                              VR: 4m

 

This is a
short cave located on the same limestone outcrop as Cave 1.  It is used by monks
as a retreat.  The passage soon chokes and the floor has been excavated in a
couple of places, probably for guano.

 

It is of
interest to note that Cave 1 and Cave 2 are at the same altitude as the old
fossil system above Tham Yai Nam Nao, but are 2km to the north-east.

 

Caves Visited By The 1992
Expedition

 

The caves
described below have not been found by the SMCC expeditions.  The descriptions
are taken from Standing (1992) and Dunkley (1995).  These descriptions are
repeated here as the 1992 report is not widely available (there are now copies
in the National Caving Library and the Shepton Mallet Caving Club library). 
Tham Yai Nam Nao, Tham Yai Nam Nao Resurgence, Tham Pha Rai (Wet Sink), Tham
Phaya Naak (Bamboo Cave), Tham Monhwa (Tree Forest Cave) and Cave 11 (Cliff Cut
Path Cave) which were visited in 1992 have also been explored by the SMCC and
are described above.

 

Note:  In the
1992 report the phrase "south-west" was found to be a typographical error for
"south-east" in the Tham Pha Rai description.

 

Tham Phra

Other names:
The Monk's Cave

Length: ~30m

"On our
second trip into the forest, our guides led us to a fascinating group of caves
situated about 50m up a cliff.  A lack of suitable maps coupled with the dense
forest cover prevents any precise description of the location, but the place is
obviously well known by the locals, and the entrances are visible from some
distance away.

A series
of wooden ladders and walkways lead up from the base of the cliff, held together
with rusty nails and bamboo lashings.  Rotten sections had obviously been
patched up and the whole thing appeared relatively safe.  About 50m up, the
level of the series of entrances is reached, and precarious bamboo platforms
tied into nearby tree trunks head off around the cliff, allowing access to all
the caves.

The main
cave is about 5m high, 10m wide and extends back into the cliff for about 10 or
12m, providing one of the most perfect rock shelters imaginable.  According to
the guides, the cave was inhabited by the monks in the rainy season.

The monks
had obviously been using the cave for a long period of time and had transformed
it into a comfortable dwelling place.  The floor had been leveled and neatly
covered with bamboo slats.  At one side was a fireplace and the cave contained
numerous ladles and other utensils as well as a small cupboard of pots and
pans.  Growing out of the floor near the front was a small tree (which we were
told was an apple tree), and right on the edge, growing out over the drop, were
three other trees which had obviously been cultivated there.  These bore
paw-paws which the guides cut down and cooked.  The view out across the forest
was very impressive as we were well above the level of the tree-tops.

Other
chambers connected to the main cave contained sleeping platforms and blankets,
with space for 6 or 8 people to live quite comfortably."

 

Tham Pha
Phrik

Other names:
Chilli Cliff Cave

Length: ~150m

"A stream
sink through boulders about 500m from the base of the cliff containing Tham
Phra.  A climb down through boulders leads into a series of small chambers with
a tight wet passage at the bottom.  A feeling of breathlessness, together with
noticing our carbide lamps burning very yellow and frequently extinguishing
suggested foul air, so we explored no further.  Another small passage containing
the stream was followed for about 100m."

 

Tiger Eats
Pig Cave

Length:
~100m              VR: ~40m

”A small
entrance up on a hillside leads to a chamber with many bats.  A short pitch
through boulders in the floor was found to be choked.  Another chamber was found
and a pitch in the floor of this has been descended for about 20m.  It appeared
to continue for another 20m or so, but lack of rope prevented further
exploration."

 

Hunter's
Stream Cave

Length: ~30m

"A
moderately large stream sink was followed in crawling sized passage for about
30m to a sump pool.”

 

Tham Puay

Other names:
Fertilizer Cave

Length:
~50m                VR: ~15m

”A 30m
long rift leads to a 15m pitch and larger passage which rapidly become blocked. 
There is evidence of guano having been dug out for use as fertiliser."

 

Miserly
Spirit Cave

Length: ~30m

"A smaller
collapse entrance about 8m high, not far from Tree Forest Cave [Tham Monhwa]. 
Total length is about 30m." A brief attempt was
made to look for this cave in January 2006, but without success.

 

Tham Huai
Nam

Length: ~15m

"A few
kilometres south or south-west of [Tham Yai Nam Nao], an active stream sink
opening into a canal with diminishing air space."

There is not
a Huai Nam marked on the 1:50,000 map.

 

Tham Huai
Pong

Other names:
Tham Haipong

"South or
south-west of [Tham Yai Nam Nao], two streams sinking with the way on blocked by
debris."

There is not
a Huai Pong marked on the 1:50,000 map.

 

Wild Boar
Cave No. 1

Length: ~15m

"A few
kilometres south or south-west of [Tham Yai Nam Nao], a 15m deep shaft with no
way on."

 

Wild Boar
Cave No. 2

Length: ~5m

"Near
[Tham Huai Nam] and [Wild Boar Cave No. 1], a small cave with no way on."

 

Cave PE36

Length: ~15m

"A few
kilometres south or south-west of [Tham Yai Nam Nao], large chamber at the base
of a cliff."

There is a
possibility that this cave is Tham Pak Now which is at the base of a cliff to
the south-west of Tham Yai Nam Nao. 

 

Geology and Hydrology

 

Various
regional studies on the structural geology and lithology of the Nam Duk basin
have been made, but the only paper that has been seen is the overview paper by
Fontaine (2002).  However, all these papers are listed in the references. The
1:250,000 geology map has also been used in compiling this section.

 

The main
limestone outcrop trends north-west to south-east from Tham Yai Nam Nao. This
outcrop is 10km long and thins from 3km wide to 500m wide as you progress
south-east from Tham Yai Nam Nao.  About 2km to the east another limestone
outcrop is shown on the geological map, but it is only about 7km long and 500m
wide.  In the field this second outcrop is seen as a row of isolated cliffs
formed from vertically bedded limestone.  A couple of small caves were found in
one of these cliffs.  The Permian limestones show significant karst features,
particularly very large dolines which are up to 1km across and 200m deep.

 

Nam Nao
National Park is located in the elongated north – south trending Nam Duk Basin
which separates the Khao Khwang Platform of Central Thailand from the Pha Nok
Khao Platform of Northeast Thailand.  The present geographical distribution of
the different lithologies is explained by displacement, caused by a north –
south trending strike-slip fault. The geology map shows the Permian limestone
outcrop is the axis of an anticline. An east-west fault forms the northern edge
of the outcrop and the anticline appears to plunge to the south-east with the
limestone disappearing below the overlying sandstones.

 

The caves of
the Nam Nao National Park are formed in limestones of the Pha Nok Formation
which is of Lower-Middle Permian age.  Fontaine & Salyapongse (2001) report that
the limestone in the northern part of the Nam Nao National Park is over 600 m
thick. The limestone is very rich in diverse fossils: algae with green algae,
fusulinaceans, corals in the lower part and brachiopods indicating that the

limestone was formed in a shallow marine environment.  These fossils date the
limestone from Murgabian to Late Midian.  The limestone is overlain by black
shale and then by a relatively small body of limestone which contains
foraminifera, but no fusulinaceans have been found so far and it might belong to
the Triassic.

 

Our own
observations show the limestone to be grey and massively bedded.  There are also
abundant thin chert beds and these indicate a dip of between 30°
and 90°
towards the north-east.  The dip to the north-east has resulted in most of the
surface landforms (ridges and valleys) and the major streamway in Tham Yai Nam
Nao trending north-west to south-east. 

 

These Pha Nok
Formation limestones are bordered to the east and west by the Middle Permian Nam
Duk formation and to the north by the Upper Triassic Huai Hin Lat Formation. 
Although the geology map describes these formations as being comprised of
shales, limestones and conglomerates they appear to be mainly sandstones.

 

A detailed
geomorphological study has not been made.  However, it was immediately seen that
there is an older, fossil system overlying the more recent, active system of
Tham Yai Nam Nao.  Tham Pha Ruag, Tham Song Hong, Tham Pha Pai and Tham Monhwa
are all found at an altitude of 810m to 950m, which is 110m to 240m above the
present day stream level which is at an altitude of 700-710m.  These caves have
been truncated by the erosion of the limestone massif.  It is hoped that by
finding more remnants of old caves such as these a better picture of this fossil
system can be pieced together.  In the Tham Phaya Naak area fossil cave
development is seen at four overlying levels: Tham Wi Mahn Mek (altitude 880m),
Tham Nop Pa Krauw (altitude 835m), Tham Phaya Naak (altitude 790m) and Tham Bah
Dahn (altitude 730m).

 

Of interest
in Tham Yai Nam Nao is the capture of the stream by newer passages.  The Tourist
Cave and Main Cave are the original route for the stream and the Tourist
entrance is an old resurgence.  The stream was then captured by a smaller
passage (the passage from the streamway junction to the downstream sump) leaving
the large Main Cave dry (though the stream may overflow into this passage in the
wet season).  The stream from Tham Pha Rai used to flow all the way to the Tham
Yai Nam Nao streamway, but has been recently captured by a very small, immature
and impassable passage. This stream certainly overflows along its old route in
the wet season.

 

Tham Yai Nam
Nao has extensive clastic deposits throughout the cave.  In the old resurgence
passages of the Tourist Cave and Main Cave these are mainly mud and sand with
recent roof collapse boulders nearer the entrance.  At the junction with the
main streamway these floor deposits are between 3m and 4m thick.  In the main
streamway there are extensive deposits of cemented sandstone cobbles, similar to
those seen in the caves near Umphang in Tak province.  The 2004 Series streamway
has mainly fine clastic deposits of sand, silt and mud with plenty of recent
organic material which has been brought into the cave.  In the 1992 Series the
deposits are of large clastics with sandstone cobbles seen along the length of
the passage.  The boulder chamber towards the end of the 1992 Series is a large
collapse feature.  The boulders have been heavily corroded by acidic water and
are very crumbly. 

 

A few basic
measurements have been made of the surface and underground streams.

 

Cave	Location	Alt.   m	Date	Flow   cumecs	Temp   °C	pH	Total hardness ppm	Ca ppm	Mg ppm	Test temp °C
Tham Yai Nam Nao	Outside cave	670	29/12/2003	-	21.2	7.6	280	240	40	25
Resurgence	Outside cave	670	01/01/2004	-	21.1	-	320	260	60	23
	Outside cave	670	10/01/2004	-	21.5	-	-	-	-	-
	Outside cave	670	11/01/2004	0.087	-	-	-	-	-	-
Tham Yai Nam Nao	Junction with main cave	696	10/01/2004	-	20.7	-	-	-	-	-
Tham Pha Rai	Stream at entrance	730	01/01/2004	0.017	-	-	260	180	80	23
	Stream at entrance	730	03/01/2004	-	16.4
	Upstream of junction	714	03/01/2004	-	20.8	-	-	-	-	-
	Downstream of junction	714	03/01/2004	-	18.6	-	-	-	-	-
Banana doline	47Q 0769935 1874078	800	08/01/2004	-	-	-	280	220	60	34
Elephant doline	47Q 0770086 1873625	840	08/01/2004	-	-	-	260	220	50	28
Tham Pak Now valley	47Q 0766343 1873626	705	07/01/2004	-	-	-	260	200	60	29

 

The
temperature of the stream sinking at Tham Pha Rai is of particular note.  This
is an exceptionally low temperature for Thailand and is probably due to the
surface stream flowing under vegetation cover from the 1,000m high sandstone
hills to the east.  Fortunately, from the caving point of view, this stream soon
meets an inlet which is considerably warmer.  This stream must also come from
the same hills as the main stream so it is odd that there is such a marked
difference in temperature.

 

The only
known resurgence in the area is the Tham Yai Nam Nao Resurgence. Along the
eastern edge of the limestone outcrop perennial streams are known to run off the
sandstones of the Nam Duk Formation into the 'Banana' doline, 'Elephant' doline
and Doline 728 to sink into Tham Pha Rai, near Cave 26 and in Sink 1
respectively.  Another, larger, stream flowing from the south-east most probably
also sinks in Doline 728 upstream of Cave 26.  The south-west of Doline 728 has
not been explored, but other streams are likely to flow off the sandstone hills
here to sink in this very large doline.  The water sinking in 'Elephant' doline
and flowing through Tham Bah Dahn is almost certainly the source of the water in
the 2004 Series in Tham Yai Nam Nao.  The water seen in Cave 26 possibly flows
into the upstream end of Tham Bah Dahn and then onto the 2004 Series.

 

Two sinks for
the Tham Yai Nam Nao 1992 Series stream have been found: the 1992 Inlet entrance
and the 1992 Series Sink.  In contrast to the 2004 series feeder streams the
tributaries to the 1992 Series appear to only flow for a short distance over
limestone and are not sourced on non-karst rocks.

 

Tham Yai Nam
Nao has a catchment of 32km² and an average annual rainfall of 1.18m.  In
January 2004 the flow from the Tham Yai Nam Nao Resurgence was measured at
0.09m³/s.  Working on the basis of a 212 day dry season (November to May) the
wet season flow at the resurgence would be approximately 2.75m³/s.  It is
estimated that 15% of the total flow comes from the 'Banana' doline via Tham Pha
Rai, 70% from 'Elephant' doline and Doline 728 via the 2004 Series and 15% from
Doline 748 and Doline 771 via the 1992 Series.

 

In January
2004 the stream in Tham Yai Nam Nao was flowing all the way along the main
streamway and there was no stream flowing in the 1992 Series just upstream of
the junction with the 2004 Series.  However, on the 8 and 9 April
2004 the water level in the main streamway was a lot lower and it was possible
to reach the downstream sump without swimming.  Three days later, on the 12
April, the stream had stopped flowing at the junction with the main cave and was
not flowing for a couple of hundred metres upstream of this junction.  The
stream was still flowing in Tham Pha Rai and this cave’s inlet to Tham Yai Nam
Nao.  At the upstream end of the 1992 Series, beyond the boulder chamber, there
was a small stream flowing.  The main stream in the 2004 Series was still
flowing quite strongly.  The surface stream thought to feed this branch of the
cave, in the 'Elephant' doline, was seen to be flowing the day after the
underground visit.  On a visit in July 2005 to the main streamway the water
levels were not any higher than they had been in January despite recent
thunderstorms.

Biology

 

This section
details the casual observations made of the life in the caves.  No specimens
have been taken and only a couple of animals have been identified to species
level.  However, some ecological observations are reported.

 

A couple of
pale coloured fish were seen just downstream of the sump in Tham Yai Nam Nao
Resurgence.  However, no fish have been seen in the Tham Yai Nam Nao streamways.
The fish were not caught or observed closely, but if they prove to be true cave
adapted fish they are likely to be a new species as no other cave fish are known
from this hydrological basin which feeds into the Chayo Phraya River. 

 

Bats are
found in all the caves, but because there are an estimated 130 species of bats
in Thailand they have not been identified though several distinct types can be
observed. The largest number of bats have been found in the tourist section of
Tham Yai Nam Nao where they roost near the third entrance on the ceiling of a
large chamber. There are guano deposits here, but they are not particularly
extensive and without an obvious associated fauna. In July 2005 bats were also
heard above the breakdown chambers at the end of the Tourist Cave. One type of
bat was found in numbers along the streamways in both Tham Pha Rai and Tham Yai
Nam Nao.  They were medium sized, grey bodied and were easily disturbed.  Once
disturbed they appeared to be particularly clumsy fliers and would crash into
the survey tape, the water and into cavers.  They were able to take off again
from the water surface or swim to the edge where they would climb up the walls. 
This type of bat favoured small, low chambers over pools of water. There were
occasionally found a long way into the cave, including the far end of the 2004
Series streamway in Tham Yai Nam Nao and it is thought that this indicates a
possible entrance nearby.  These colonies of bats would not always be found in
the same place, one group seen in January were not in the same place in April. 
In Cave 1 a long eared bat was photographed.  A few individuals of a small bat
species were found a long way into Tham Yai Nam Nao and we had the impression
that they were hunting the small insects attracted to our lights.  This
behaviour has also been observed from caves in Tak province. The chamber in Tham
Pak Now was used as a roost by a few large bats.

 

A rat
inhabited the crawl at the end of Tham Nop Pa Krauw and had a mutually scary
moment when coming face to face with the first caver through. The rat has not
been seen since the crawl was later enlarged considerably.

 

The Cave
Racer snake (Orthriopus taeniurus, previously Elaphe taeniura) has
not been found in any of the caves of this area, but a green snake was met in a
low airspace section of the link between Tham Pha Rai and Tham Yai Nam Nao.

 

The usual
cave crickets (Rhaphidophoridae: ?Diestrammena spp.)
and cave huntsman spiders (Sparassidae: ?Heteropoda
spp.) were found in most of the larger caves.  Long-legged cave centipedes
(Chilopoda: Scutigeramorpha) has only been seen at the end of the tourist
section of Tham Yai Nam Nao. A 15cm long 'normal' centipede (Chilopoda:
Scolopendromorpha: ?Scolopendra subspinpes) was seen in Tham Phaya Naak.
Although the bite of these fearsome looking creatures is not usually fatal you
might wish it was after  three days of excruciating pain.

 

Firefly
beetles were an unusual find in the tourist section of Tham Yai Nam Nao, but
these were accidental visitors.  Adult caddisflies or mayflies have been a
nuisance in the Tham Yai Nam Nao streamway. Again these were accidental visitors
which had been washed into the cave as larvae. A 4cm long, pale coloured shrimp
was found in one of the pools just before the Tham Yai Nam Nao downstream sump.

 

Two species
of moth have been found aestivating in the caves.  An impressively large noctuid
moth (Noctuidae: Cataocalinae: Erebus macrops (Linmaeus, 1768)) was seen
in Tham Pha Pai and a segment of wing from the same species was found in Cave 1.
Erebus macrops is found throughout south, south-east and east Asia.  This
behaviour of aestivating in caves has also been seen in Tham Loe Pu, Tak
province and in northern Laos. A medium sized moth (?Noctuidae or ?Geometridae)
was seen in Tham Pha Pai.  In January 2005 harvestmen or daddy-long-legs spiders
(Opiliones) were found aestivating in the wet entrance to Tham Pha Rai and the
1992 Inlet entrance to Tham Yai Nam Nao in such large numbers that the walls of
the cave appeared to be hairy.  This behaviour has recently been reported from
caves in northern Laos, but has apparently not been mentioned in the literature.

 

Surveying and Mapping

 

A total of
12.50km of underground surveying and 0.25km of surface surveying has been
carried out by the Shepton Mallet Caving Club in the Nam Nao National Park.

 

All cave
entrances co-ordinates have been fixed using handheld GPS units, either an 8
channel Garmin 45XL or by 12 channel Garmin Etrex, V or 76.  In addition all the
footpaths, dirt tracks and roads were tracked by GPS and have been used to draw
the map in this report.  The waypoints and tracks from the GPS units were
downloaded into the Fugawi moving map program.  Fugawi was used to plot these
data onto a scanned map and this was used as a base for drawing the maps with
Adobe Illustrator.

 

All the
surveys and co-ordinates used in this report use the UTM grid and are on the
Indian 1954 (Thailand-Vietnam) datum.  Conversions from the GPS default WGS84
datum were by the GPS unit’s internal algorithms.

 

The cave
surveys were done using a 30m tape and handheld compass and clinometer.  In a
couple of the smaller caves and in the tourist cave section of Tham Yai Nam Nao
a Leica laser rangefinder was used for passage widths and ceiling heights.  The
instruments were not calibrated to true or grid north, but they were calibrated
with respect to each other.  The cave surveys are thus to a BCRA (1976) 3c
grade.

 

The cave
survey data was processed and managed using the Walls cave survey program.  The
surveys were drawn using either Adobe Illustrator CS based on a SVG export from
Walls or by the traditional pen and paper method.  The UIS (1999) symbol set has
been used for the cave surveys.

 

Expedition Members

 

Tony Blick                     Dec 03/Jan 04, Dec 04/Jan 05

Dave Briggs                   Dec 05/Jan 06

Geraldine Collett            Dec 05/Jan 06

Phil Collett                    Dec 03/Jan 04, Dec 04/Jan 05,
Dec 05/Jan 06

Claire Dummer               Jan 05, Dec 05/Jan 06

Paul Dummer                Jan 05, Dec 05/Jan 06

Martin Ellis                    Dec 03/Jan 04, Apr 04, Dec
04/Jan 05, Jul 05,

Dec 05/Jan 06

Glyn Francis                  Jan 05

Ivan Hollis                      Dec 03/Jan 04, Apr 04, Dec
04/Jan 05, Dec 05/Jan 06

Lee Hollis                      Dec 05/Jan 06

Sean Howe                    Dec 03/Jan 04

Dave Owen                    Dec 04/Jan 05, Dec 05/Jan 06

 

Expedition Diaries

2003

Thu 27 Nov        Ivan & Martin leave
UK.

Thu 25 Dec        Sean & Phil leave UK.

Fri 26 Dec         Sean & Phil arrive in
Bangkok and drive to Ayutthaya to meet Tony.

Sat 27 Dec        Everyone meets up in
Lom Sak.

Sun 28 Dec       Visit Nam Nao National
Park HQ.

                        Tham Yai Nam
Nao: survey from 6m ladder to entrance.

Mon 29 Dec       Tham Yai Nam Nao:
planned long trip with guides, but stopped by bad air at                      
low, wet section. Survey back to 6m ladder.

Tue 30 Dec        Look at limestone
outcrop about 1 km to the NE of the park boundary.                              
Survey Cave 1 and Cave 2.

Wed 31 Dec      Walk along north-east edge of national park.
Survey Tham Pha Pai and Tham Pha Hok.

2004

Thu 1 Jan          Walk along north-east
edge of national park. Locate Tham Pha Rai.

Fri 2 Jan            1) Tham Pha Rai:
survey and extend downstream end of cave.

                        2) Locate Cave 5
3.5 km SE of Tham Yai Nam Nao.

Sat 3 Jan          1) Tham Pha Rai:
continue survey and pushing downstream.

                        2) Survey Cave 5
and find and survey Tham Nop Pa Krauw.

Sun 4 Jan          1) Survey Tham Par
Hong and  Tham Phu Talor (Phu Pha Man                                         
National Park, Khon Kaen).

                        2) Visit Tham
Par Hong. Explore track to south of  H12.

Mon 5 Jan         1) Tham Pha Rai:
survey and push upstream

                        2) Hire guides
and locate Tham Song Hong and Tham Pha Ruag.

Tue 6 Jan          Hire guides and
survey Tham Song Hong and Tham Pha Ruag.

Wed 7 Jan         Explore western edge
of national park and find Tham Pak Now.

Thu 8 Jan          1) Tham Yai Nam Nao:
discovered bad air had cleared and explore main                 streamway for 1
km. Survey Tham Yai Nam Nao Resurgence.

                        2) Plan to walk
to bottom of doline beyond Tham Pha Rai doline, but meet a                      
herd of elephants so turn back (‘Elephant' Doline).

Fri 9 Jan            1) Tham Yai Nam
Nao: survey 850m in Main Cave and streamway.

2) Explore
2004 Series for approx. 2.5 km to sump.

Sat 10 Jan         Tham Yai Nam Nao:
extend survey 950m up 2004 Series.

                        Sean, Phil &
Tony leave Lom Sak.

Sun 11 Jan        Tham Pha Rai: collect
rigging kit which had been left at top of pitch.

Mon 12 Jan       Ivan & Martin leave Lom
Sak.

 

Mon 29 Mar       Ivan & Martin leave UK.

Wed 7 Apr         Ivan & Martin arrive
in Lom Sak.

Thu 8 Apr          Tham Yai Nam Nao:
survey downstream to sump.

Fri 9 Apr            Tham Yai Nam Nao:
tourist trip to streamway.

Sat 10 Apr         Hire guides and visit
Tham Song Hong, Tham Pha Pai and Tham Pha Hok.                         Shown
entrance to Tham Monhwa, but stopped at pitch.

Sun 11 Apr        Visit Tham Phaya
Nakarat & Tham Lai Tang (Phu Pha Man National Park,                         Khon
Kaen).

Mon 12 Apr       Tham Yai Nam Nao:
explore 1992 Series to duck beyond Boulder Chamber.

Tue 13 Apr        Tham Yai Nam Nao:
survey Tham Pha Rai inlet.

Wed 14 Apr       Tham Yai Nam Nao:
survey 700m upstream in 2004 Series.

Thu 15 Apr        Walk to 'Elephant'
Doline and follow stream part way down towards
                                   swallet.

Fri 16 Apr          Tham Pak Now: survey
cave.

Sat 17 Apr         Martin & Ivan leave
Lom Sak.

 

Thu 23 Dec        Martin arrives in
Bangkok.

Sat 25 Dec        Dave O, Ivan & Phil
leave UK.

Sun 26 Dec       Dave O, Ivan & Phil arrive in Bangkok and
meet Martin. Drive to Ayutthaya to meet Tony.

Mon 27 Dec       Drive to Lom Sak.

Tue 28 Dec        Tham Yai Nam Nao: link with Tham Pha Rai.
Check Main Passage and Tourist Cave for leads. Investigate between Second and
Bat entrances.

Wed 29 Dec      Tham Monhwa: survey main
passage

Thu 30 Dec        Tham Yai Nam Nao:
survey 700m in 1992 Series.

Fri 31 Dec         1) Tham Par Hong: descend rift and explore
base of limestone outcrop.

                        2) Walk through 'Elephant' Doline to
the hills above Doline 728. Find Cave 17.

2005

Sat 1 Jan          Walk to 'Elephant' Doline stream via gully
down from col at head of 'Banana' Doline.

Sun 2 Jan          1) Find & explore
Cave 11.

                        2) Find Tham
Phaya Naak. Dig through end choke in Tham Nop Pa Krauw.

Mon 3 Jan         1) Through trip from
Tham Pha Rai to Tham Yai Nam Nao surveying link.

                        2) Walk to
Doline 715 from the Tham Yai Nam Nao ranger station.

Tue 4 Jan          1) Walk ridge between
Tham Pha Ruag and Cave 11.

                        2) Walk to Doline 728 via 'Elephant'
Doline – find Caves 19 and 20 and Sinks 1 and 2.

Wed 5 Jan         Tham Yai Nam Nao:
survey 1.2 km in 2004 Series to upstream sump.

Thu 6 Jan          Surveyed Tham Phra
(Phu Pha Man National Park, Khon Kaen).

Fri 7 Jan            Tham Monhwa:
descend pitches and survey entrance area.

Sat 8 Jan          1) Tham Yai Nam Nao:
explore 1992 Series to gour and inlet passage.

                        2) Visit Tham
Erawan (Nong Bua Lam Phu) and Tham Pha Sawan (Loei)

Sun 9 Jan          Walk and find main sink for 1992 Series in
Tham Yai Nam Nao.

Martin & Tony
leave Lom Sak.

Mon 10 Jan       Tham Yai Nam Nao: push 1992 Series Inlet to
entrance and dig below gour to find 250m passage ending at aven. 11 hr trip.

Tue 11 Jan        Walk over surface to
new entrance at end of 1992 Series Inlet.

Wed 12 Jan       Dave O, Phil & Ivan
leave Lom Sok.

Thu 13 Jan        Paul, Claire & Glyn
leave UK.

Fri 14 Jan          Paul, Claire & Glyn arrive Bangkok.
Everyone meets in Ayutthaya.

Sat 15 Jan         Dave O & Phil leave Thailand. Martin,
Ivan, Paul, Claire & Glyn drive to Lom Sak.

Sun 16 Jan        Tham Yai Nam Nao: survey 700 m of the 1992
Series to the ducks beyond the boulder chamber.

Mon 17 Jan       Tham Phaya Naak: survey cave.

Tue 18 Jan        Tham Yai Nam Nao: tourist trip to showcave.

Wed 19 Jan       Walk to Doline 715 from Tham Yai Nam Nao
ranger station. Find Caves 13, 14 and 15.

Thu 20 Jan        Tham Phaya Naak: finish survey and
unsuccessfully attempt to find link to Tham Nop Pa Krauw. Explore Cave 5.

Fri 21 Jan          Drive to Pha Phueng Wildlide Sanctuary
headquarters (Khon San, Chaiyaphum) and talk to head ranger.

Sat 22 Jan         Tham Pha Rai to Tham Yai Nam Nao through
trip.

Martin leaves
Lom Sak.

Sun 23 Jan        Tham Nop Pa Krauw: survey cave. Shown Tham
Bah Dahn in 'Elephant' Doline.

Martin leaves
Thailand.

Mon 24 Jan       Tham Bah Dahn: explore and survey cave.

Tue 25 Jan        Tham Singh Toh (Pha Phueng Wildlife
Sanctuary, Chaiyaphum): survey & photograph, but didn't have tackle to fully
explore the cave.

Wed 26 Jan       Tham Nop Pa Krauw: Descend pitch, but run
out of rope. Tham Wi Mahn Mek: explore and survey above pitch, aural connection
to Tham Nop Pa Krauw.

Thu 27 Jan        Claire, Paul, Glyn & Ivan leave Lom Sak.
Drive to Ayutthaya then onto Bangkok.

Fri 28 Jan          Day in Bangkok.

Sat 29 Jan         Claire, Paul & Glyn leave Thailand.

Sun 30 Jan        Ivan leaves Thailand.

 

Tue 5 Jul           Tham Yai Nam Nao: Martin on solo trip to
main streamway – water level low.

 

Mon 26 Dec       Martin & Ivan arrive in Bangkok from New
Zealand.

                        Paul, Claire, Dave O, Lee and Dave B
leave UK.

Tue 27 Dec        Everyone meets up in Ayutthaya.

Wed 28 Dec      Drive to Lom Sak. Meet up with Phil &
Geraldine.

Thu 29 Dec        1) Tham Yai Nam Nao: planned big surveying
trip to the end of 1992 Series was stopped by high CO2 just beyond the show
cave.

                        2) Phil & Geraldine on surface walk
to the west of Tham Yai Nam Nao.

Fri 30 Dec         1) Cave 5: descended until it got too
small.

                        2) Tham Nop Pa Krauw: pitches
descended until visual connection with Tham Phaya Naak, but not enough rope to
descend.

                        3) Tham Wim Mahn Mek: surveyed around
the top of the pitch and aural connection with Tham Nop Pa Krauw.

Sat 31 Dec        1) Tham Phaya Naak: photography and confirm
visual connection with Tham Nop Pa Krauw.

2006

Sun 1 Jan          Look at quarry near Lom Sak.

Mon 2 Jan         1) Tham Nop Pa Krauw: rig pitch into Tham
Phaya Naak and survey connection.

                        2) Find Caves 23, 24 and 25 near Tham
Wim Mahn Mek and Tham Bah Dahn.

Tue 3 Jan          Long walk on the eastern path past Banana
and Elephant dolines, descend following stream in the next doline to Sink 1 then
join path from Tham Phaya Naak.  Follow this path south to Cave 26.  Return via
path from Tham Phaya Naak to Banana doline.

Wed 4 Jan         1) Cave 14: descend pitch and connect to
1992 Series in Tham Yai Nam Nao.  Find Cave 27.

                        2) Look for caves near Tham Monhwa.

                        Geraldine leaves Thailand.

Thu 5 Jan          Leave Lom Sak and move to hotel in
Chumphae.

Fri 6 Jan to        Explore caves in the Pha Phueng Wildlife
Sanctuary and Phu Pha Man

Mon 9 Jan         National Park.

Tue 10 Jan to     Cha-Am: visit caves in
Khao Sam Roi Yot National Park and waterfall in

Fri 13 Jan          Kaeng Krachan National
Park.

Sat 14 Jan         Paul, Claire, Lee,
Phil, Dave B and Dave O leave Thailand.  Martin and Ivan                        
return to Lom Sak.

Sun 15 Jan to    Look for and visit
various caves in Phetchabun and Loei provinces.

Fri 20 Jan

Sat 21 Jan         Martin and Ivan leave
Thailand.

 

References

 

1. Dunkley, John R. (1995) The
   Caves of Thailand Speleological Research Council Ltd., Sydney
   pp58-60
2. Elliott, S. & Cubitt, G. (2001) The National Parks
   and other Wild Places of Thailand New Holland Publishers (UK) Ltd., London
   pp90-93
3. Ellis, Martin (2003) The SMCC Expeditions to Umphang
   & Mae Sot, Tak Province, Thailand Shepton Mallet Caving Club Journal
   Series 11 No. 3 pp75-138
4. Ellis, Martin (2004) SAM in Siam Shepton Mallet
   Caving Club Newsletter Vol. 40 No. 6 pp140-146
5. 
   Ellis, Martin & Barrett, Dave (2001) Thailand Expedition February
   2000 Report Shepton Mallet Caving Club Journal Series 10 No. 8 pp247-272
6. Fontaine, Henri (2002) Permian of Southeast Asia: An
   Overview Journal of Asian Earth Sciences Vol. 20 pp567-588
7. Fontaine, Henri & Salyapongse, S. (2001) A Murgabian
   to Lower Triassic Sequence Exposed from Khao Tham Yai to Khao Pa Khi,
   Northeast Thailand: A Preliminary Report Journal of the Geological Society
   of Thailand Vol. 24 No. 1 pp43-47
8. Helmcke, D. & Kraikhong, C. (1982) On the
   Geosynclinal and Orogenic Evolution of Central and Northeastern Thailand
   Journal of the Geological Society of Thailand Vol. 5 No. 1 pp52-74
9. Helmcke, D. & Lindenberg, H.G. (1983) New Data on the
   Indosinian Orogeny from Central Thailand Geologische Rundschau Vol. 72 No.
   1 pp317-328
10. Helmcke, D. (1982) On The Variscan Evolution of
    Central Mainland Southeast Asia Earth Evolution Sciences Vol. 4 pp309-319
11. Helmcke, D. (1994) Distribution of Permian and
    Triassic Syn-orogenic sediments in Central Mainland SE Asia Proceedings of
    the International Symposium on the Stratigraphic Correlation of Southeast
    Asia, Department of Mineral Resources, Bangkok. pp123-128
12. Helmcke, D., Weber, K., Ingavat, R. & Nakornsri, N.
    (1985) Orogenic Evolution of NE Thailand During the Upper Paleozoic
    Proceedings of the Conference on Geology and Mineral Resources Development of
    NE Thailand, Khon Kaen, pp31-39
13. Kononenko, Vladimir S. & Pinratana, Amnuay (2005)
    Moths of Thailand Vol. 3 Noctuidae Part 1 Brothers of Saint Gabriel in
    Thailand, Bangkok 261pp
14. Owen, David R. (2005) On the Dating of Caving
    Expeditions by the Use-by Dates on Noodle Packets: A Scientific Study
    Shepton Mallet Caving Club Newsletter Vol. 42 No. 2 p30
15. Standing, Nick (1992) Report of the 1992 Expedition
    to the Nam Nao National Park, Thailand unpublished report 11pp
16. Steiner, Helmut (2005) Biospeleological Notes On Laos
    in Dreybrodt, Jeorg & Laumanns, Michael (eds.) The Unknown North of Laos
    (Karst and Caves of the Provinces Luang Phrabang and Luang Nam Tha)
    Berliner Hohlenkundliche Berichte Band 16 pp92-97
17. Wielchowski, C.C. & Young, J.D. (1985) Regional
    Facies Variations in Permian Rocks of the Petchabun Fold and Thrust Belt,
    Thailand Conference on the Geology & Mineral Resource Development of NE
    Thailand, Khon Kaen University, pp41-55
18. National Parks Department website:
    http://www.dnp.go.th/parkreserve/asp/style1/default.asp?npid=36&lg=2

 

Maps

 

1.      
Phu Kradung 1:50,000, sheet 5342 IV series L7017 US Army
Topographic Command (1969)

2.      
Amphoe Nam Nao 1:50,000, sheet 5342 IV series
L7017S, Royal Thai Survey Department, Bangkok (1992)

3.      
Changwat Phetchabun 1:250,000, sheet NE 47-16 series
1501S, Royal Thai Survey Department, Bangkok (1986)

4.      
Changwat Phetchabun, 1:250,000, sheet NE 47-16 series
1501S, Geological Survey Divison, Department of Mineral Resources (1976
published 1984)

5.      
MapMagic CD-ROM Road Map of Thailand 2005-2006 ThinkNet
Co., Ltd. (2005)

 

Acknowledgements

 

The rangers at the Tham Yai Nam
Nao substation: Khun Khumpan Paichan (Head Ranger), Tiam, Manu, Bo, Pong and the
rest of the guys for allowing us access to the cave, showing a lot of interest
in our work and plying us with fruit wine and food after our trips.

Nopodon and the other monks
living at Tham Nop Pa Krauw for encouraging our explorations, hospitality and
showing us Tham Wi Mahn Mek and Tham Bah Dahn.

Ms Rattana Lakanawarakul and the
Royal Forest Department for granting permission to explore and survey the caves
in the national park. Thanks also to Dean Smart for helping to obtain this
permission.

The Ghar Parau Foundation for
£175 (2003/4) and £150 (2004/5) in grant aid.

EVA Airways for granting the
2004/5 expedition an additional 5 kg baggage allowance.

Nick Standing who was on the
1992 expedition for digging out his old notes and photographs to supply further
details of the caves explored in 1992.

John Dunkley in Canberra,
Australia for providing a copy of the 1992 Nam Nao expedition report.

Dave Checkley in Manchester for
providing a copy of his 1989 report on the Phu Kheio Wildlife Sanctuary
expedition.

Ed Waters & Mark Sims for the
loan of photographic and surveying equipment.

 

 

Cave Data

 

Name	Entrance	Co-ordinates	Altitude	Length	VR
Tham Yai Nam Nao	Tourist Second Bat Cave 14 1992 Inlet	47Q 0767316 1874832 47Q 0767329 1874822 47Q 0767332 1874774 47Q 0767954 1873736 47Q 0767459 1872603	693 m 711 m 729 m 740 m 750 m	9,817 m	76 m
Tham Pha Rai	Stream Upper	47Q 0768798 1874006 47Q 0768805 1874000	730 m 738 m
Tham Phaya Naak	North South	47Q 0769802 1872166 47Q 0769611 1871896	790 m 801 m	1,285 m	133m
Tham Wi Mahn Mek   Tham Nop Pa Krauw	Main Eastern	47Q 0769709 1872041 47Q 0769783 1872067 47Q 0769657 1872017	880 m 880 m 835 m
Tham Bah Dahn		47Q 0769885 1872279	760 m	655 m	29 m
Tham Monhwa	Main Second	47Q 0768555 1873314 47Q 0768529 1873376	952 m 947 m	365 m	55 m
Tham Song Hong	Lower Upper	47Q 0768150 1874261 47Q 0768183 1874172	820 m 836 m	215 m	23 m
Tham Yai Nam Nao Resurgence	Main Upper	47Q 0767335 1874880 47Q 0767350 1874873	673 m 687 m	130 m	11 m
Tham Par Hong	Upper Lower Small	47Q 0767755 1854078 47Q 0767755 1854078 47Q 0767755 1854082	885 m 878 m 879 m	105 m	11 m
Cave 5		47Q 0769664 1871759	776 m	~100 m	~35 m
Cave 1	Main Upper	47Q 0769310 1875793 47Q 0769357 1875797	830 m 841m	90 m	14 m
Tham Pha Pai		47Q 0768307 1874020	860 m	84 m	7 m
Tham Pak Now		47Q 0766600 1872899	757 m	75 m	15 m
Cave 26		47Q 0770376 1871080	760 m	~65 m	~2 m
Tham Pha Ruag		47Q 0767936 1874604	860 m	59 m	11 m
Tham Pha Hok	Main Second Pitch	47Q 0768482 1874257 47Q 0768495 1874248 47Q 0768465 1874257	760 m 759 m 771 m	51 m	13 m
Cave 11		47Q 0768765 1873158	922 m	~45 m	~18 m
Cave 2		47Q 0769402 1875587	860 m	43 m	4 m
Cave 10		47Q 0769673 1871887	825 m	35 m	2 m
Cave 7		47Q 0768404 1874234	780 m	~ 20 m	~ 5 m
Cave 14		47Q 0767954 1874736	740 m	~20 m	~20 m
Cave 21		47Q 0768481 1873364	948 m	~20 m	~15 m
Cave 24		47Q 0769858 1872052	875 m	~20 m
Cave 25		47Q 0769928 1872305	750 m	~20 m	~5 m
Cave 8		47Q 0768408 1874263	770 m	~ 10 m	~ 5 m
Cave 12		47Q 0767824 1853906	855 m	~10 m
Cave 17		47Q 0771387 1871712	900 m	~10 m	~0 m
Cave 23		47Q 0769838 1872087	894 m	~10 m
Cave 27		47Q 0767950 1873900	750 m	~10 m	~10 m
Cave 18		47Q 0768009 1874348	830 m	~5 m	~2 m
Cave 20		47Q 0770062 1871551	755 m	~5 m	~5 m
1992 Series Sink		47Q 0767784 1872237	770 m	~3 m	~3 m
Cave 19		47Q 0770214 1871540	755 m	~2 m	~2 m
Draughting holes		47Q 0768453 1874218	775 m
Cave 13		47Q 0767727 1874364	810 m
Cave 15		47Q 0768372 1873656	820 m
Cave 22		47Q 0768490 1873372	931 m
Sink 1		47Q 0770114 1871638	755 m
Sink 2		47Q 0770233 1871587	755 m