Koh Samui is located in the Gulf of Thailand off the east coast of the Kra Isthmus, about 35km northeast of Surat Thani town (9°N, 100°E). It is Thailand's second largest island, with an area of 228.7 km² and a population of 47,874 (2006). It is surrounded by about sixty other islands, most of which comprise the Ang Thong National Marine Park, but also include the tourist destinations of Ko Pha Ngan, Ko Tao and Ko Nang Yuan.
The island, roughly circular in shape, is about 15km across, the central part being an almost uninhabitable mountain jungle (peak Khao Pom, 635m). The various lowland areas are connected by a single road that runs round the circumference of the island.
First inhabited about 1500 years ago, settled by fishermen from the Malay Peninsula and Southern China, Koh Samui appears on Ming Dynasty maps dating back to 1687 under the name Pulo Cornam. The name Samui is mysterious in itself. Perhaps it is an extension of the name of one of the native trees, mui, or it is a corruption of the Chinese word Saboey, meaning "safe haven".
There is one town, Na Thon, on the west coast of the island, with a major port for fishing and inter-island transportation. Each of Samui's many beaches is also nominally considered a town, due to the number of hotels, restaurants and bars that have sprung up in recent years.
