Mu Ko Ang Thong

Mu Ko Ang Thong Marine National Park was created in 1980 in the Gulf of Thailand, in Surat Thani province, north-west of Ko Samui, and protects some 102 km² around an archipelago of forty-two islands.

Its name means "golden bowl" and describes the shape of the group: limestone islands with vertical, vegetation-covered walls emerging from a shallow sea, the remains of a drowned karst. Many are pierced by caves and arches, and on the island of Ko Mae Ko a collapsed doline holds the Talay Nai, an inner saltwater lagoon of emerald green connected to the sea by underground conduits, which is the park's most widely reproduced image.

The islands preserve lowland evergreen forest and mangroves in the inlets, with a fauna that includes smooth-coated otter, langurs and a varied coastal and forest birdlife. The seabeds are less spectacular than those on the Andaman side, but they hold seagrass meadows and recovering reefs. The archipelago inspired the setting of Alex Garland's novel The Beach, although the film was shot elsewhere. The pressure of daily excursions from Ko Samui and Ko Pha Ngan is the main management challenge.