Yedikule Fortresses are one of the most important open-air museums of Istanbul. The famous Golden Port (Porta Aurea) which was built as triumphal arch at the behest of Emperor Theodosius the First (in 390) was combined with city walls which the Emperor Theodosius the Second had Anthemiusa constructed.
It is claimed that The Golden Port was constructed with marble towers as a whole in the period of Theodosius the Second (in 413).
The Golden Port was the most important gate through which many emperors coming back from battles passed by celebrations and magnificently.
A five cornered and actinoid citadel (garrison) was constructed by combining the bulwarks with three towers added 4 years later from the conquest of Istanbul by Fatih Sultan Mehmed in May of 1453. So the constructions of Byzantine and Ottoman era were integrated.
Fatih Sultan Mehmed who went to Skopje for Serbia campaign assigned the chief inspector of Istanbul, ‘Karıstiran Mustafa Bey’, to construct Yedikule Fortresses with coordination and to restoration of the city.
Beside the usage of fortresses as state's prison in the period of Ottoman Empire, it played host for the first fisc (Hazine-i Humayun) and valuable documents of Ottoman. In that period there were a guardsman on the castle, fifty troops and their houses, their shelters and their storerooms in garrison of the Fortress. Small mosque in the yard succeeded to remain standing until 1887.
Yedikule Fortresses are also known as Yedikule Dungeons because of the prisoners locked in there.
Yedikule Fortresses which experienced many earthquakes, battles, fires took its recent form after the detailed restorations between the years of 1958 and1970 by Master Architect Cahide Tamer who was one of the first woman architects of our country.