Just before the Fatih Bridge are the majestic structures of Rumeli Hisar? and Anadolu Hisar? (Fortress of Anatolia). Mehmet the Conqueror had Rumeli Hisar? built in a mere four months in 1452, in preparation for his siege of Byzantine Constantinople. For its location, he chose the narrowest point of the Bosphorus, opposite Anadolu Hisar?, which Sultan Beyaz?t I had built in 1391. By doing so, Mehmet was able to control all traffic on the strait, cutting the city off from resupply by sea.