The island of Ko Mak is situated in the East of the Gulf of Thailand, 35 kilometers from the mainland, and is the third largest island in Trat Province, after Ko Chang and Koh Kood. With an area of 16 square kilometers Ko Mak has 27 km of coastline, many long sandy beaches, and a few hills.[10] The island is home to approximately 800 locals and renowned for its beautiful beaches, having been included in the U.K's Sunday Times 10 most beautiful beaches list in 2006.[11] Ko Mak has a temple, a primary school, 3 fishing villages, a market and a health center.[12]
It is possible to walk to Ko Kham, a smaller island less than 1 km northwest from Ko Mak during low tide. Ko Phi, a tiny island also north west from Ko Mak but southwest from Ko Kham.