The Dome of Soltaniyeh is known as the third most famous dome in the world, in terms of height after the Cathedral of Santa Maria del Fiore and Hagia Sophia mosque. This dome is a spectacular attraction of Zanjan province that has been registered on the UNESCO World Heritage list. The Dome of Soltaniyeh with the weight of 1600 tons, has been standing for 700 years with subsidence of eight centimeters.
This structure has 8 elevated porticos and about 50 chambers, including an area which is also similar to a chamber. The dome of this construction weighs 200 tons and is situated on pillars, bearing an area of 50 sq.m. each if separated or cut across. This structure is made of a mixture of gypsum and to a lesser proportion limestone.
The outer shell of the dome has been covered by turquoise blue and ultramarine marquetry tiles. Soltaniyeh dome is two-shelled and the building has various rich decorations.
Wall paintings, lattice brickworks, wooden and stony decorations, plaster and brick muqarnas and some Qur’anic inscriptions are among different kinds of architectural decorations in Soltaniyeh.