Castles in Trabzon
The castle walls stretch from the coast to the hills in the city centre, and are the best-preserved ruins of the region.

The centre of the old fortified town is Ortahisar, literally Middle Castle, with the upper citadel upstream and Ortahisar Cami and several gates. This mosque, also known as Fatih Cami, was probably a church in the 3rd century and later the main cathedral during the Trapezuntine Empire. Fatih Tower was constructed by Empress Irene in 1340, and used as a meeting-place for Trabzon aristocracy. There is little left of the upper citadel, once the Comnenius palace, but a few crumbling walls.

Arsenal: It is mentioned that the tower, which is known as Fatih Tower or Irene Tower Kulesi and has no definite information due to no inscription, is constructed by Empress Irene (1340 – 1341) as meeting place of Trabzon aristocracy.