Kolah Farangi edifice and 'Ali Qapu frontispiece are the remnant of Arg Saltanati from safavid era. It is reconstructed on Qajar era and is called Chehelsotun. It is octangular and has two storey. The roof of the first storey is covered by Maqrans with new designs and
the roof of the second storey is covered by Khenche. This building is used as a calligraphy museum.