Ang Thong National Marine Park

Ang Thong - the name means golden bowl - is a national park covering forty-two islands of limestone karst in the Gulf of Thailand, west of Koh Samui. The islands are steep, forested and largely uninhabited, and the park exists to keep them that way; there is no resort development.

Two things draw most visitors. The first is the Emerald Lake (Talay Nai) on Koh Mae Ko, a saltwater lagoon enclosed by cliffs and reached by a steep stairway. The second is the viewpoint above Koh Wua Talap, the park headquarters island, which looks out over the whole archipelago and involves a demanding climb. Kayaking and snorkelling make up the rest of a typical day.

The park is only reachable by boat, on organised day trips from Koh Samui and Koh Phangan. It closes to visitors for part of the year during the monsoon, and rough weather can cancel departures at short notice.