The Caves of Phetchabun has 126 caves and other sites of speleological interest. These caves include the third longest cave in Thailnd, the 10.4 km long Tham Yai Nam Nao and the 133 m deep Tham Phaya Naak, both of which are in the Nam Nao National Park.
Phuket is the most popular tourist destination in Thailand. Although Phuket Island itself has no karst many visitors take boat trips to the outstanding karst scenery in Phang Nga Bay to the north-east of Phuket. On the mainland Phang Nga town is surrounded by impressive karst massifs and there are a couple of one kilometre long stream caves in the town. To the north of Phang Nga there are several long stream caves near Ban Tham Thong Lang. This guidebook has 123 caves and other sites of speleological interest and 22 surveys. The longest and deepest cave is Tham Racaha Phuttha (1,504 m long and 21 m deep).