The lesser developed
With the differing levels of to-be-expected development concerning hot springs in Thailand, there seems to be no rule, bar one: the more remote, the less developed. But even this rule will have to thrown out of the window.
Chaiya district's (Surat Thani province) distant claim to fame is the Suan Mokkh temple. Established just 50 years ago (or earlier) this forest temple was home to Ajahn Buddhadasa Bhikkhu, one of Thailand's most famous monks (source).
But besides the attraction of the road side temple complex, just a one km walk away is a hot spring; delitefully ...
Read the full entry on Soaking in Siam.