The national park is located in the southern part of Krabi province and consists of several islands. The two largest islands are Koh Lanta Noi and Koh Lanta Yai. Koh Lanta Yai is popular and frequently visited by tourists.

The park was created in 1990 and occupies 134 sq. km. Koh Lanta was once known by the Malay name Pulao Satak, which means Long Beach Island. Later, many Thais, both Muslims and Buddhists, moved to the island and it became known as the island of "a million eyes" ("Lanta" in Thai). Koh Lanta is quite a mountainous island, especially near the southern tip, part of its beaches are pebbly, and part is with fine white sand.

Clan Chao Lei, or "sea gypsies" lives on Koh Lanta Yai. The clan still practices many of its ancient customs and rituals, such as launching ceremonial boats to bring good luck and prosperity on the full moons of the sixth and eleventh months.