Arg of Tabriz, is the remnants of a large acropolis fortification and city wall in downtown Tabriz, Iran. Its structure is visible from far distances in downtown Tabriz, if not blocked by the newly erected highrise buildings.
The structure was initially a compound, containing a great vaulted mosque, adjoining prayer halls and libraries, a vast courtyard containing a huge reflecting pool, and a mausoleum—all surrounded by a containing wall. It was built in 14th century during the Ilkhanate era. The point of pride for the building was that its vaulted ayvan was larger than the famous historic vault of Chosroes/Kisra or the Taq Kisra at Ctesiphon/Mada'in.
Wikipedia https://en.wikipedia.org/wiki/Arg_of_Tabriz
Coordinates 38°4'20.729" N 46°17'19.889" E