Moon, Venus and Jupiter in the evening sky of World Heritage Site of Soltaniyeh Dome near Zanjan, Iran. The historic city of Soltaniyeh used to be the capital of Ilkhanid rulers of Persia in the 14th century. Its name translates as “the Imperial”. The dome is the oldest double-shell dome in the world. The estimated 200 ton dome stands 49 meters tall from its base.