This hidden treasure, i.e. a mountain lake known as the Emerald Lake and nicknamed the Blue Lagoon, is located on the 240 meter high pinnacle of Koh Mae Koh.

Koh Mae Koh is an island that is part of Moo Koh Angthong, a National Marine Park in Surat Thani. In Thai, the lake is known as Thale Nai, literally ‘Inner Sea’ or the ‘Sea Within’.