Dome of Soltaniyeh (Gonbad-e Soltaniyeh) is an amazing architectural masterpiece located near Zanjan which you will visit in your Iran trip. This gargantuan 49-meter building is one of the exceptional constructions of Iran which was established to be used as a mausoleum. The inner walls of Dome of Soltaniyeh, adorned with thuluth and arabesque script are where you don't want to miss. Considering the diameter of the opening, Dome of Soltaniyeh has the 3rd largest dome of the world and is the greatest historical site belonging to Ilkhanid era! The superlative Dome of Soltaniyeh, inscribed on UNESCO heritage list in 2005 is one of the impressive historical sites you can visit on your Iran tour.