It is situated on the Tracean side of the Istanbul
Bosphorous. It was built by Sultan Mehmet the Conqueror in 1452 to prevent aid
from north reaching Byzantine. It took 4 months to build with 1000 masons and
2000 workers. The three towers were built by Çandarlı Halil Pasha, Saruca Pasha
and Zaganos Pasha and are named after them. The fortress has 5 gates and lies
over an area of 30.000 m².