Ko Lanta Yai is an island in the Strait of Malacca off the west coast of Thailand, between the Phi Phi Islands and the mainland. It is administratively part of Krabi Province, most of which is on the mainland. Together with neighboring Ko Lanta Noi, which forms the Ko Lanta archipelago, and several other islands, it forms the amphoe of Ko La…Ko Lanta Yai is an island in the Strait of Malacca off the west coast of Thailand, between the Phi Phi Islands and the mainland. It is administratively part of Krabi Province, most of which is on the mainland. Together with neighboring Ko Lanta Noi, which forms the Ko Lanta archipelago, and several other islands, it forms the amphoe of Ko Lanta District.