The citadel of Ankara was already built by the Hittites as a military garrison. It is situated on a 978 m high hill in the northern part of the present centre of Ankara.

Over the centuries, the castle has been used by different peoples and empires. When the Galatians appeared in Anatolia in 278 BC, they made Ankara their capital. During this time the citadel was extended to two parts of the city (inner and outer city). Of the former twenty towers of the outer city, only a few remain today. The walls of the inner city, on the other hand, have been well preserved to this day.

In 25 BC Ancyra, as Ankara was then called, became the capital of the Roman province of Galatia. During Roman rule, the citadel was used as an army camp.
During the division of the Roman Empire after the death of Emperor Theodosius I in 395, the city fell to the Eastern Roman Empire, later called the Byzantine Empire. The impressive fortification walls, in which spoils of Roman origin, including column drums and gravestones, were used, date from this period.