Dome of Soltaniyeh is one of the most important examples of Ilkhanid architecture that has had a great effect in historical monuments architecture in the world; we can see this influence in the architecture of Cathedral of Saint Mary of the Flowers in Florence.
After Dome of Cathedral of Saint Mary of the Flowers in Italy and Dome of Hagia Sophia in Turkey, Dome of Soltaniyeh is the third largest dome in the world.
The dome registered in Iran's National Heritage in 1931. It was also registered in the list of UNESCO world Heritage as the seventh Iranian classic in Tir 24th, 2005.
Source: Travital.com