Koh Mak is located in the East of the Gulf of Thailand, between Koh Chang and Koh Kood, about 38 kilometers from the coast. Koh Mak is the third biggest island of the Mu Koh Chang National Park after Koh Chang and Koh Kood, with an area of 16 square kilometers; it is mostly flat.

The journey from Laem-Ngob Port to Koh Mak takes around 3 hrs by ferry. However, it can be faster, only 45 mins, by speedboat.

Koh Mak is the ideal island for relaxing on the beautiful beaches, reading books and kayaking around the island. The island has a circumference of 27 kilometers, and white sandy beaches stretch from the north-west of the island round to the south. The atmosphere on the island is peaceful and quite laid back. The sand on the beach is also packed enough to allow biking on the beach as well. Ao Ta Nid, Ao Phai, Ao Suan Yai and Ao Khao, are the most popular beaches.