Therasia is a piece of sub-continental land surrounded by water.
 It forms the southernmost member of the Cyclades group of islands, with an area of approximately 73 km2 (28 sq mi) and a 2011 census population of 15,550
=== Water and sewerage ===As the island lies in a rain shadow between the mountains of Crete and the Peloponnese water seems to have been scarce at least from post-eruption times

