Soltanieh Royal Citadel

Iran, Iran

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The Soltanieh Royal Citadel, also known as Cohan Dej, is the most important surviving ancient citadel from the Ilkhanid (Mongol Ilkhanate) period in Iran, located in the center of the city of Soltaniyeh in Zanjan Province.

It is a large fortified complex surrounded by a moat and a high rampart, with a square-shaped area measuring roughly 314 by 296 meters, and it originally featured 16 towers and two main gates (north and south) built of green limestone, forming the heart of the Ilkhanid capital city of Soltaniyeh.

The citadel was developed during the reign of Ghazan Khan and reached its full urban scale under Sultan Mohammad Khodabandeh (Öljaitü), who built the city as a symbolic capital of the Ilkhanate over about ten years in the early 14th century (704–713 AH). Just southwest of the citadel lies the famous Dome of Soltaniyeh, the monumental brick mausoleum of Öljaitü, which is the largest brick dome in Iran and the third-largest brick dome in the world, and which UNESCO recognizes as a World Heritage Site adjacent to the royal citadel.

Although much of the greater Ilkhanid city of Soltaniyeh was destroyed after Timur’s invasion and later declines, the surviving elements of the citadel and especially the dome demonstrate the scale, architectural sophistication, and political importance of this once-majestic Mongol-Persian capital.