Koh Samui is located in the Gulf of Thailand, about 35km northeast of Surat Thani town (9°N, 100°E). It is surrounded by about sixty other islands, most of which comprise the Ang Thong National Marine Park, but also include other tourist destinations Ko Pha Ngan, Ko Tao and Ko Nang Yuan.
The island is roughly circular in shape, and is about 15km across. The central part of the island is an (almost) uninhabitable mountain jungle (peak Khao Pom, 635m) and the various lowland areas are connected together by a single road, that covers the circumference of the island.
The old capital is Nathon, on the southwest coast of the island, and remains the major port for fishing and inter-island transportation. Nathon is the seat of the regional government, and the true commercial hub of the Samui locals. It has a charming pace, and is almost small enough to walk everywhere. The old Chinese shop houses along the middle street wisper of an exotic history.
Each of Samui’s primary beaches is now also nominally considered a town, due to the number of hotels, restaurants and bars that have sprung up in recent years.