On a mound raised about 30 meters above the rest of the city lies Erbil Citadel, the ancient center of the Iraqi city of Erbil, and the oldest continuously occupied settlement in the world. The houses along the exterior of the citadel form a fort-like structure, while the interior is filled with narrow alleys, archways, and intricate brickwork.
Erbil Citadel is a fortified ovoid-shaped ancient mound. Seen from above, the mound of earth sprouts from the otherwise flat surrounding terrain. The elevation is due to millennia of settlements built one on top of the other.