The ancient Venetian fortress of Kalidona buit in the 16th century (around 1571) on the island of Spinalonga (originally a peninsula, separated from the mainland by an artificial channel), protecting Agios Nikolaos from the seaside, was never conquered. After 1897, it became a station for the leprous. The infected with leprosy lived there in old Venetian and Turkish houses, growing various crops plants and breeding animals living their own life, but couldn´t leave the place. The camp ceased to exist only in 1957 when the rest of the ill was transported to Athens.

South of the fortress there is a peninsula connected with the resort of Elounda by a dam. You will find there the remains if the Doric town of Olous, mostly under under the water surface, being a frequant target of divers. Art its time, the town was a significant port of east Crete.