Lasithi (Greek: Λασίθι) is the easternmost regional unit on the island of Crete, to the east of Heraklion. Its capital is Agios Nikolaos, the other major towns being Ierapetra, Sitia and Neapoli. The mountains include the Dikti in the west and the Thrypti in the east. The Sea of Crete lies to the north and the Libyan Sea to the south.To the east of the village of Elounda lies the island of Spinalonga, formerly a Venetian fortress and a leper colony.