The Citadel Town of Erbil, or Qala't Erbil, is an impressive elevated settlement that has been inhabited continuously for millennia. Although it's exact origins cannot be traced with certainty, there are strong archaeological indications and finds, however, to indicate that it goes back to some 6000 years. The fortified town itself must have been present during to the Assyrian Period (1365-612 BC), or some 3000 years ago.
Some archaeologists believe that the site has been settled in since the Neolithic to Mid Bronze Age period (6000-1500 BC).