Spinalonga is a barren, arid rocky islet, with an area of 85,000 sq. m., lying in the mouth of the natural harbour of Elounda in Lasithi Prefecture, Crete. The islet was fortified in antiquity, to protect the ancient city of Olous. Towards the end of the 16th century, the Venetians, as part of their great fortification works to defend Crete, built on Spinalonga one of the most important bastion-type seaward fortresses of the Mediterranean, designed according to the bastion system of fortification by Genese Bressani and Latino Orsini. At strategic points in the fortifications are set the Michel and Moceniga or Barbariga demilunes, major works of fortification architecture.