Place: Zanjan province
The mausoleum of Oljaytu was constructed in 1305-1313 A.D. in the city of Soltaniyeh, the capital of the Ilkhanid dynasty, which was founded by the Mongols. Soltaniyeh is one of the outstanding examples of the achievements of Persian architecture and a key monument in the development of its Islamic architecture. The octagonal building is crowned with a 50 m tall dome covered in turquoise-blue faience and surrounded by eight slender minarets. It is the earliest existing example of the double-shelled dome in Iran.