The Rumeli Fortress was built in 1452 by Sultan Mehmet II prior to the conquest of Istanbul, whose aim was to block any possible sea support which might have come from the Black Sea to assist the flailing Byzantines. Therefore, the Rumeli Fortress was to be situated on the narrowest point of the Bosphorus strait, facing another smaller fortress, the Anadolu Fortress, already erected on the Asian side. The construction work on this giant castle finished after 4 months and 19 days.
Now it serves as a museum, displaying the canons that were used during the conquest. There is also an outdoor mini-amphi-theater used during the various music festivals in Istanbul.
Book daily Istanbul sightseeing tours at www.toursistanbul.com from a range of guided tours.