Town of Soltaniyeh lies in north-west Iran and the main attraction of this town is the Dome of Soltaniyeh, which is a part of several ruins. This is the Mausoleum of Il-khan Öljeitü also known as Muhammad Khodabandeh.
Having the oldest double-shell dome in Iran, this structure was erected from 1302 to 1312 AD. 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 (Istanbul, Turkey).
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.
Photo credits: Vaibhav Shetty at Globing Around