Yoros Castle sits on a hill surrounded by steep bluffs overlooking the confluence of the Bosphorus and the Black Sea.
The future site of Yoros Castle was originally settled by the Phoenicians and Greeks for trading and military purposes.
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.
In 1624 a fleet of 150 Cossack caiques sailed across the Black Sea to attack Bosphorus towns and villages.
Greek inscriptions remain carved on the walls to 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.