Ko Samui is the district with Islands in the Gulf of Thailand and is located in the District of Surat Thani. 1 in 3 areas as plains surrounded by mountains, is one of the major tourist attraction in the Gulf of Thailand coast. Amphoe Ko Samui has the total combined area of other islands approximately 252 Rai. Ko Samui alone , has an area of approx. around 228 Rai. It is the third largest island in Thailand after Phuket Island , and Ko Chang.