Koh Taen is an island about 15 kilometers off the mainland and five kilometers south of Koh Samui in the Gulf of Thailand. It is part of the Samui archipelago, which includes about 60 other islands. North of Koh Taen lies the Angthong National Park. Koh Taen is inhabited by about 20-30 people.
The island has several beaches that are suitable for snorkeling. The island is surrounded by coral reefs, which survived into the 1980s and partially recovered from the popular dynamite fishing in the region.
Koh Taen has an extensive mangrove forest on the southwest coast with beautiful wildlife. Monitor lizards can be seen quite often during a walk through Koh Taen. There is still a small temple in Koh Taen with a fresh water source on the beach.
The island is named by the bats because of its large population, which flies to Koh Samui every night for food search.