The Citadel of Erbil is an UNESCO World Heritage Site. It defines the center of the city in all senses: it marks the geographical center from where the city irradiated in a concentric plant and the social and commercial core also.
The mound where nowadays the citadel stands has been occupied by humans since pre-historic so it's hard to define the date of construction, but most of what we see now was the result of Ottoman military engineering.
Unfortunately the entrance has been closed for some time, apparently by instructions of UNESCO.
The citadel saw lots of action along its long life. For example, it sustained the Mongols for a while before fallinbg into their hands.
From Wikipedia:
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visit link)
"The Erbil Citadel locally called Qellat, is a tell or occupied mound, and the historical city centre of Erbil in the Kurdistan Region of Iraq. The citadel has been included in the World Heritage List since 21 June 2014.
The earliest evidence for occupation of the citadel mound dates to the 5th millennium BC, and possibly earlier. It appears for the first time in historical sources in the Ebla tablets in modern Syria around 2000 BC, and gained particular importance during the Neo-Assyrian period. During the Sassanian period and the Abbasid Caliphate, Erbil was an important centre for Christianity. After the Mongols captured the citadel in 1258, the importance of Erbil declined. During the 20th century, the urban structure was significantly modified, as a result of which a number of houses and public buildings were destroyed. In 2007, the High Commission for Erbil Citadel Revitalization (HCECR) was established to oversee the restoration of the citadel. In the same year, all inhabitants, except one family, were evicted from the citadel as part of a large restoration project. Since then, archaeological research and restoration works have been carried out at and around the tell by various international teams and in cooperation with local specialists. The government plans to have 50 families live in the citadel once it is renovated.
The buildings on top of the tell stretch over a roughly oval area of 430 by 340 metres (1,410 ft × 1,120 ft) occupying 102,000 square metres (1,100,000 sq ft). The only religious structure that currently survives is the Mulla Afandi Mosque. The mound rises between 25 and 32 metres (82 and 105 ft) from the surrounding plain. When it was fully occupied, the citadel was divided in three districts or mahallas: from east to west the Serai, the Takya and the Topkhana. The Serai was occupied by notable families; the Takya district was named after the homes of dervishes, which are called takyas; and the Topkhana district housed craftsmen and farmers.
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Erbil was conquered by the Muslims in the 7th century. It remained an important Christian center until the 9th century, when the bishop of Erbil moved his seat to Mosul. In the middle of the 10th century, Erbil came under the rule of Hadhabani Kurds until 1063 when it was taken over by the Seljuk Turks. From the first half of the 12th century until 1233, Erbil was the seat of the Begteginids, a Turcoman dynasty that rose to prominence under the reign of Zengi, the atabeg of Mosul. In 1183, Zain ad-Din Yusuf, ruler of Erbil, shifted his allegiance to the Kurdish Ayyubid Sultanate. In 1190 when Zain ad-Din Yusuf died, his older brother Muzaffar al-Din Gökböri, who was previously governor of Edessa, became the new governor of Erbil. He created a lower town around the city on the citadel mound and founded hospitals and madrasahs. When Gökböri died in 1233 without an heir, control of Erbil shifted to the Abbasid Caliph al-Mustansir after he had besieged the city.
When the Mongols invaded the Near East in the 13th century, they attacked Erbil for the first time in 1237. They plundered the lower town but had to retreat before an approaching caliphal army and had to put off the capture of the citadel. After the fall of Baghdad to Hülegü and the Mongols in 1258, they returned to Erbil and were able to capture the citadel after a siege lasting six months. Hülegü then appointed a Christian governor to the town and there was an influx of Jacobite Christians, who were allowed to build a church.
As time passed, persecutions of Christians, Jews and Buddhists throughout the Ilkhanate began in earnest in 1295 under Oïrat amir Nauruz. This manifested early on in the reign of the Ilkhan Ghazan. In 1297, after Ghazan had felt strong enough to overcome Nauruz' influence, he put a stop to the persecutions.
During the reign of the Ilkhan Öljeitü some of the Christian inhabitants retreated to the citadel to escape persecution. In the spring of 1310, the Malik (governor). Despite Mar Yahballaha's best efforts to avert the impending doom, the citadel was at last taken by Ilkhanate troops on 1 July 1310, and all the defenders were massacred, as were all the Kurdish inhabitants of the lower town.
After Battle of Chaldiran in 1514, Erbil came under control of Soran emirate, a semi-independent Kurdish emirate under the Ottoman Empire. In the 18th century Baban Emirate took the city but it was retaken by Soran ruler Mir Muhammad Pasha of Rawanduz in 1822. The Soran emirate continued ruling over Erbil until it was retaken by the Ottoman Turks in 1851. Erbil became part of the Mosul Vilayet in Ottoman Empire until World War I, when the Ottomans were defeated by the British Empire. The town had approximately 3,200 inhabitants, including a sizeable Jewish minority.
Modern period
This central straight way was made after demolishing some houses. The Ahmadi (northern) Gate appears in the background while the dome of the hammam (public bath) is on the right
During the 20th century, the citadel witnessed significant urban and social changes. A 15-metre (49 ft) high steel water tank was erected on the citadel in 1924, providing the inhabitants with purified water, but also causing water damage to the foundations of the buildings due to increased water seepage. The number of inhabitants gradually declined over the 20th century as the city at the foot of the citadel grew and wealthier inhabitants moved to larger, modern houses with gardens. In 1960, over 60 houses, a mosque, and a school were demolished to make way for a straight road connecting the southern gate with the northern gate. Some reconstruction works were carried out in 1979 on the citadel's southern gate and the hammam. In 2007, the remaining 840 families were evicted from the citadel as part of a large project to restore and preserve the historic character of the citadel. These families were offered financial compensation. One family was allowed to continue living on the citadel to ensure that there would be no break in the possible 8,000 years of continuous habitation of the site, and the government plans to have 50 families live in the citadel once its renovated. In 2004, the Kurdish Textile Museum opened its doors in a renovated mansion in the southeast quarter of the citadel."