Sultan Mehmet the Conqueror built Rumelian Castle in the narrowest point of the channel to control the Bosphorus in 1452, a year before the conquest of Istanbul. It was built in a short time like four months. It aimed to block the aids coming to the Byzantine from Anatolian Castle across the shore.
Castle consists of three big towers, smaller bastions between them and walls. Minaret body seen from the courtyard of the castle remains from the mosque built the Conqueror period and collapsed in 1907. Stage platform next to the minaret hosts concerts of famous artists in summer. There are also cisterns under the platform.
Magnificent view of the Bosphorus can be seen over the walls which can be taken up from the stairs in the courtyard.