Koh Mak is located in the East of the Gulf of Thailand, 40 kilometers from the mainland. Koh Mak is the third biggest island in Trat province after Koh Chang and Koh Kood, with an area of 16 square kilometers; it is mostly flat. The island has a circumference of 27 kilometers, and white sandy beaches. No wonder that The Sunday Times newspaper named Koh Mak as one of its "World’s Top 10 Secret Beaches" in late 2006. Away from the two main beaches on the northwest and northeast coasts, the scenery mainly comprises rubber and coconut plantations.