The castle of Antirio (also known as the Castle of Roumeli, from the Ottoman word denoting Central Greece) is a coastal fortress built by the Ottoman Turks to control the entrance to the Gulf of Corinth (with the help of the Castle of Morea across the sea). The first castle was built within three months in 1499 by Sultan Bayezid II. In 1532 the garrison blew up the fort (and themselves) rather than surrender to the Venetians. The Ottomans rebuilt it and lost it again and again (to the Knights of Malta and the Venetians) before finally securing it for good in 1715. The fort is a kite-shaped enclosure reinforced with six bastions, a moat, and gun batteries commanding the entrance to the gulf.