Kasos lies southwest of Karpathos, and east of Crete. The island lies within the subtropical zone, being at 35ºN latitude. Adjacent to the island is the Strait of Kasos, through which some of the Modified Atlantic Water enters the Sea of Crete. Its shape is elliptic and resembles that of Rhodes. The main island has a surface of 49 square kilometres, and it is 17 km long and 6 km wide. It is very mountainous, with its highest mount being Mt. Prionas, which is 550 meters high. There is fresh water on the island. Lawrence Durrell is rather disparaging about the island, begrudging it a mere 22 words in a brief comparison to Karpathos, calling it a “smaller, stonier version of the same sort of thing.”