The Rumeli Fortress, located within the borders of Sariyer District of Istanbul, was built by Fatih Sultan Mehmet in 1452. The purpose of the construction of the fortress was to block the aid coming to the city from the north of the Bosphorus and to prevent possible attacks when the city was besieged.
The fortress, built in a short time of four months, is located right opposite the Anadolu Fortress. It has an area of 30 decares and consists of three large towers and walls. The timber used in its construction was obtained from Izmit and Karadeniz Ereglisi, while the stones were obtained from different parts of Anatolia and the ruined Byzantine buildings in the surrounding area.
It has four main gates, as well as a secondary gate called the Cemetery Gate. The fortress has a total of four towers, three large ones named Saruca Pasha, Halil Pasha, and Zaganos Pasha, and the younger one named Zaganos Pasha Jr. There are 13 large and small zodiac signs within the fortress.
In the museum garden, there is an open display featuring cannons, roses, terracotta, stone works, and a part of the chain that is said to have closed the Golden Horn. There is no indoor exhibition hall or warehouse.
The lighting design concept for the Rumeli Fortress in Istanbul incorporates the criteria of the Istanbul Lighting Masterplan. The aim is to capture the fortress's impact on the city from day until late at night. By using light to reflect the texture and architectural details on the fort's walls, the design brings out the colour and quality of the structure. It also strategically decreases light levels towards the upper elevations and highlights the towers to emphasize the fortress's grandeur.
During the restoration, an open theater structure was added to the fortress. This allows the Rumeli Fortress to host various events during the summer period, as it is allocated to various institutions and organizations by the Ministry of Culture and Tourism.