Dome of Soltaniyeh - Zanjan
                
                
                
                    
                    
						It is stated that the Soltaniyeh skylight windows are similar to the sun clocks which had been used for religious issues. Two-shelled domes are invented here for the first time in the architecture history of the world. The Soltaniyeh brick dome is the third tall dome in the world after Florence Santa Maria Cathedral and Istanbul Hagia Sophia.