The result of a gigantic volcanic eruption around 3,500 years ago, the island of Santorini (or Thera) is now a crescent of rock rising over three hundred metres from the sea. It curls around the flooded crater, or caldera, and the resulting deep sheltered lagoon is ideal for visiting cruise ships. Most of the population lives along the crater rim, or on the land behind the cliffs that slopes gently down to the sea on the eastern side of the island. The diamonds in Santorini’s rock tiara are its capital Fira and the villages of Imerovigli and Oia, which perch on the crater’s edge, Away from the caldera, the black volcanic beaches of the east coast are essential stops on a Santorini holiday.