forty-year occupation gave the castle its commonly used nickname - the Genoese Castle. After Sultan Mehmed II’s conquest of Constantinople in 1453, the presence of the Genoese in such a strategic location posed a threat to the new Ottoman capital and within a few years they were driven out. Mehmed II then refortified the walls, and constructed a customs office, a quarantine centre and a check point, as well as garrisoning the site. Bayezid II (1481–1512) later added a mosque within the castle walls. Cossack raids plagued the Ottoman Empire from time to time. In 1624 a fleet of 150 Cossack caiques sailed across the Black Sea to attack Bosphorus towns and villages. Sultan Murad IV (1623–1640) refortified Anadolu Kavağı as a defence against them. This proved instrumental in securing the region against such seaborne raids. Under Osman III (1754–1757), Yoros Castle was once again refortified. Later, in 1783 Abdülhamid I added more watchtowers. After this time, the castle gradually fell into disrepair. By the time the Turkish Republic was declared in 1923, it was no longer in use. Present day The ruins of the citadel and its surrounding walls still exist, although the mosque, most of the towers and other structures have been lost. Greek inscriptions remain carved on the walls o this day, along with the symbol of the Palaiologos family, who ruled Byzantium until its fall. Yoros Castle and the village of Anadolu Kavağı make a popular day trip from the centre of Istanbul. From 2018 to 2021 excavations were carried out at the castle but it is now open to the public again. Much of the area surrounding the castle is in the hands of the Turkish military and closed to visitors. See also Rumeli Kavağı Byzantine Empire Ottoman Empire Gallery References Rough Guide to Istanbul. Summer-Boyd, Hilary, and John Freely. Strolling Through Istanbul. Istanbul: SEV Matbaacilik ve Yayincilik A.S., 1997 External links Yoros Castle photo gallery Drone footage of the castle from July 2022 Castles in Turkey Ottoman fortifications Ancient Greek archaeological sites in Turkey Buildings and structures in Istanbul Tourist attractions in Istanbul Bosphorus Forts in Turkey Byzantine fortifications in Turkey Ruined castles in Turkey Castles in Istanbul Province World Heritage Tentative List for Turkey