Rumeli Hisarı

Rumeli Hisarı is an Ottoman fortress on the European shore of the Bosphorus in Istanbul's Sarıyer district, built directly across from the older Anadolu Hisarı on the Asian side. Sultan Mehmed II ordered its construction in 1451 and had it completed in just four months — a remarkable feat meant to choke off Byzantine supply routes before the decisive siege of Constantinople in 1453. At this point the Bosphorus narrows to under 700 meters, making it the ideal chokepoint to control Black Sea traffic. Now a museum open Thursday through Tuesday from 09:00 to 17:00, the fortress hosts open-air concerts by well-known Turkish musicians each summer. The towers offer sweeping panoramic views over the strait.