The citadel (Iş Kale) is 200 times 800 meters, and was built by the Byzantines in the sixth century. Its present outlay is mainly the result of Seljuk additions and changes. The building times of some towers is known, i.e. the Yoğun BurÁ or Fat Tower (1212) and the Hassan Bece BurÁ. There is a mosque within the citadel - see this picture - founded by Mehmet II in 1468.
Nowadays its a shopping area with a special atmosphere.