Spinalonga is an island in the Gulf of Elounda, north-eastern Crete, in the municipality of Agios Nikolaos, Lasithi, next to the town of Plaka in the area of Kalydon. It is near the Spinalonga peninsula ("large Spinalonga") – which often causes confusion as the same name is used for both.

The island was maintained as a fortress for centuries under Venetian rule. It later became a refuge for Muslim families fearing persecution, and finally a leper colony in the early 20th century. It has been uninhabited since 1962; though it has undergone some restoration work in the years since. Today it is the second most visited tourist site in Crete, and sixth in Greece overall.

Spinalonga is a rocky island situated at the northern mouth of the gulf of Elounda. Around 750m of water separates it from the village of Plaka on the Cretan mainland to the west. To the south a narrow strip of water separates it from Kolokitha island, while the east is open to the Sea of Crete. It is only 85,000 square meters in size, and largely rocky, with steep cliffs at the northern side of the island. Elsewhere the coastline features pebble beaches that retreat into shallow waters. The highest point is in the centre-south of the island, at an altitude of around 50m.

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