Santorini is an island in the southern Aegean Sea, about 120 mi southeast of Greece's mainland. Santorini is the largest one of the Cyclades islands in the Aegean Sea. It was devastated by a volcanic eruption in the 16th century BC, forever shaping its rugged landscape. 

Santorini is essentially what remains after an enormous volcanic eruption that destroyed the earliest settlements on a formerly single island, and created the current geological crater.  The whitewashed, cubiform houses of its 2 principal towns, Fira and Oia, cling to cliffs above an underwater caldera (crater). They overlook the sea, small islands to the west and beaches made up of black, red and white lava pebbles.  It forms the southernmost member of the Cyclades group of islands, with an area of approximately 28 sq mi and a 2011 census population of 15,550. 

The municipality of Santorini includes the inhabited islands of Santorini and Therasia and the uninhabited islands of Nea Kameni, Palaia Kameni, Aspronisi, and Christiana. The total land area is 34.990 sq mi.