The city of Soltaniyeh, the capital of the Mongol Ilkhanid dynasty (1259 – 1355 CE) hosts an outstanding turquoise-blue dome, the oldest double-shell dome of Iran. This dome is the third largest dome in the world after the domes of Florence Cathedral and Hagia Sophia, and of the largest brick dome in the world.
The dome of Soltaniyeh is a proof of improvement in Iranian architecture and a key structure in the development of its Islamic architecture. Commended by Oljaytu (1280 – 1316 CE), the construction of the dome that known as his mausoleum started from 1302 and lasted for ten years. This architectural masterpiece and its innovative double-shelled dome, and elaborated interior decoration paved the way for these Perso-Islamic constructions in the Muslim world, such as the Mausoleum of Khoja Ahmed Yasavi and the Taj Mahal.
This octagonal building is crowned with a tall dome covered in turquoise-blue glazed tiles surrounded by eight slender minarets.
This building is exemplar of Azeri architecture style i.e., a combination of Persian and Mongolian architecture.
It is built on a rectangular plan on the first floor, and then the second floor gets to an even octagonal structure with seventeen meters length. Further, the third floor with a very vast terrace gives an exceptional view of the city of Soltaniyeh and surrounded pastures and mountains. The sunrays illuminated into the building reveal a specified time which ultimately help people to identify the exact time for praying and religious rituals.
This work was globally registered in 2005.