Ko Lanta is about 25 kilometres long by 3 kilometres wide. A lush mountain range separates the east and west coasts of the island.
If you are looking for Koh Lanta on a map, look for Ko Lanta Yai. It is a medium-sized island on the eastern seaboard of the Andaman Sea in the southern end of Phang Na Bay near Phi Phi Island and a 4 hour ferry ride from Phuket. It is separated from the mainland of Krabi province by its sister island Ko Lanta Noi.