Description : Soltaniyeh is a city in and capital of Soltaniyeh District of Abhar County Zanjan Province Iran. Soltaniyeh, located some 240 kilometres to the north-west of Tehran used to be the capital of Mongol Ilkhanid rulers of Persia in the 14th century. In 2005 UNESCO listed Soltaniyeh as one of the World Heritage Sites. The road from Zanjan to Soltaniyeh extends until it reaches to the Katale Khor cave.William Dalrymple notes that oljaitu intended Soltaniyeh to be "the largest and most magnificent city in the world" but that it "died with him" and is now "a deserted, crumbling spread of ruins. The central magnet of Soltaniyeh's several ruins is the Mausoleum of Il-khanoljeitu also known as Muhammad Khodabandeh traditionally known as the Dome of Soltaniyeh. The structure erected from 1302 to 1312 AD has the oldest double shell dome in Iran. This erroneous view of the construction was made by Dieulafoy but is totally disputed by Andre Godard. In Godard's view it is a normal if spectacularly large dome, with a thin skin on top for the faience and is in no way a double dome. Its importance in the Muslim world may be compared to that of Brunelleschi's cupola for Christian architecture. It is one of the largest brick domes in the world just at the theoretical engineering limit for a brick dome and the third largest dome in the world after the domes of Florence Cathedral and Hagia Sophia. The Dome of Soltaniyeh paved the way for more daring Iranian-style cupola constructions in the Muslim world such as the Mausoleum of Khoja Ahmed Yasavi and the Taj Mahal. Much of its exterior decoration has been lost, but the interior retains superb mosaics, faience and murals. People have described the architecture of the building as “anticipating the Taj Mahal.” The estimated 200 ton dome stands 49 meters tall from its base and is currently undergoing extensive renovation.