A few years ago I went to Thailand to visit a friend, do some random looking around, and dive. Here are some selected photos of Khao Sok National Park which was a real gem. We only scratched the surface but our highlight was hiring a boat on the lake and renting some kayaks. We stayed nearby in a tree house hotel, fun!
For more info, here is a link to the park: http://www.khaosok.com/#tab-id-3