Khao Sok is a national park in south Thailand located in Ban Ta Khun and the Phanom district of neighbouring Surat Thani province. The whole park covers 645 sq km. It is actually the heart of a complex of five contiguous conservation sites that comprise the largest protected forest on the Thai-Malaysian peninsula, covering over 4,000 sq km. The park is very spectacular with dripping thick native verdant rainforest, punctuated by towering outcrops of limestone cliffs or karsts, waterfalls and sparkling streams, an island studded lake, several caves, and many trails, mostly along rivers. A beautiful large reservoir was created by the construction of the Chiaw Lan Dam (also known as the Ratchaprapha Dam) across the Paseang river; this Chiaw Lan Lake occupies some 165 sq km. Limestone outcrops protruding from the lake can reach heights of 960m, which is three times the height of similar famous formations in Ao Phang-Nga. I went to a 3 days 2 nights tour in Khao Sok with my friend Kaya (a tour agent and guest house owner in Phuket). We slept on bamboo raft houses on the lake. The lake is absolutely beautiful and calm surrounded by mountains and forrest.