Moo Koh Similan National Park has been rated first by the U. S. publication Skin Diving of the top ten dive sites in the world. The Similan Islands in the heart of the Andaman Sea are indeed unparelled in their exotic beauty. If planning a visit, keep in mind that anytime between December to April is recommended, with the best month being March, because the monsoons are over and the water is clear.

The national park is established in 1982 and located in Ko Phrathong Sub-distreict, Khuraburi District, Phang-nga Province and covers 128 square kilometers, 80,000 rais, of area, 14 square kilometers of which is land composed of all the islands put together. Located along the western coastline of the Andaman Sea and in the Indian Ocean, rest these nine exotic granite islands created by upwellings of hot magma during the Teritiary-Cretaceous Period some 65 million years ago, then smoothed by glacial ice and the wave action of the sea.

Similan is really the Malaysian word for nine, as there are nine islands in the Similan group: Ko Bangu, Ko Similan, Hin Huwagralok, Ko Payu, Ko Ha, Ko Hok, Ko Miang, Ko Payan, Ko Payang, and Ko Huyong.

In 1998, the park boundary was expanded to cover Ko Tachai which is located further north of Ko Bon and the Similan group. Then the park area becomes 140 square kilometers.