Rumeli Hisarı Hakkında İngilizce Bilgi The Rumeli Fortress, or Rumeli Hisan, was built in 1452 by Sultan Mehmed the Conqueror (1451-81) as part of his efforts to conquer the city of Constantinople. Located at the narrowest point oft he Bosphorus on the European side, it is strategically placed for the control of ship traffic on the Bosphorus and directly faces the Anadolu Fortress on the Asian side of the Bosphorus. This fortress consists of three main towers, thirteen bastions, and connecting walls. The three towers which rise approximately 30 m from the ground and the walls of which range from 3 to 5 m in thickness, are named after individual Paşas, or military commanders of Sultan Mehmed, the Conqueror, such as Halil Sarıca Paşa and Zaganos Paşa. After the conquest of Constantinople in 1453, the fortress was used as a prison. It has been a museum since 1958. An outdoor amphitheatre was later added to the structure in which plays, music concerts, and cultural events are held.