Rumeli Hisari

Rumelihisarı is a medieval fortress located in Istanbul, Turkey, on a series of hills on the European banks of the Bosphorus. The fortress also lends its name to the immediate neighborhood around it in the city's Sarıyer district. Conceived and built between 1451 and 1452 on the orders of Ottoman Sultan Mehmed II, the complex was commissioned in preparation for a planned Ottoman siege on the then-Byzantine city of Constantinople, with the goal of cutting off maritime military and logistical relief that could potentially come to the Byzantines' aid by way of the Bosphorus Strait, hence the fortress's alternative name, "Boğazkesen", i.e. "Strait-cutter" Castle.