a large building with a blue dome on top of it

Soltaniyeh, located some 240 kilometres (150 mi) to the north-west of Tehran, was built as the capital of Mongol Ilkhanid rulers of Iran in the 14th century. Its name which refers to the Islamic ruler title sultan translates loosely as "the Regal". Soltaniyeh was visited by Ruy González de Clavijo, who reported that the city was a hub of silk exportation.[4]