Santorini owes of course his geographical structure to the volcanic activity in the region, so the originally round island has turned into an island with a horseshoe shape.
The island is characterized by its inner side of the island, the volcano part, the western part which is steep (caldera) and the eastern part which is smoother. Santorini covers an area of 76 km2 and mainly consists of pumice, which helped the growing of crops but also has been exported in large quantities of rock from mines. The perimeter of the island is 38 M (nautical miles) and has six large bays: Amoudi, Pano Meria, Armeni, Planos, Fira, Bali.
The highest mountain is the Prophet Elias with an altitude of 567 m and his continuation Mesa Mountain with an altitude of 365 m. The area between those two mountains is called Sellada.