Ko Samui (เกาะสมุย), (pronounced gaw (vowel like ou in cough) sà mui) is an island located in the Chumphon Archipelago in the Gulf of Thailand, some 700 km south of Bangkok and about 80 km from the eastern coastline of Southern Thailand.
An island of natural beauty and variety, Samui is home to about 40,000 full-time inhabitants, 90% of whom are Buddhist. The palm-fringed shoreline and coconut and fruit cultivation of the coastal lowlands rise to a central granite massive, the slopes of which are cloaked in virgin rainforest. At 247 km² Samui is the second-largest island in Thailand and the largest island in the Chumphon Archipelago of over 80 (mostly uninhabited) islands which form the Ang Thong National Marine Park, a kayaking and snorkelling paradise. At 25 km long and 21 km wide, Samui is big enough for serious exploration by the adventurous and fit, but can be circumnavigated in just a couple of hours by motorbike or car. The island was probably first inhabited about 15 centuries ago, settled by fishermen from the Malay Peninsula and southern China. It appears on Chinese 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".