Khao Sok National Park is a wonderful rainforest in Southern Thailand. You can stay in huts just outside the entrance and either trek independently through the trees and wildlife or hire a guide. There are: howling monkeys, gigantic flowers, and lagoons to swim in all surrounded in thick jungle.
www.khaosok.com
Khlong Sok, Phanom, Surat Thani 84250, Thailand +66 77 395 154
Google map: bit.ly/a77ImM