In the down skirts of the Bistoon Mountains by the command of Mohammad Khodabandeh the Oljayto (703-716 AH.) a town was built known as "Soltan Abad Chamchal" or "litle Baqdad". This town was constructed by the Eilkhani soltans in order to be used as the center of Kurdestan instead of "Bahar". In Bistoon excavations in Gamasiyab River banks, on a wall from Sassanide period, relics of the Ilkhanan period have been discovered. These are probably the remainders of the city reputedly known as Chamchal. The Mongol relics in Bistoon, includes a large structure which pertains a high value of importance from the architectural point of view, related to the Eilkhanian period. This building has 13 rooms, 3 porches and a few corridors. The main construction materials of the building are gypsum, mortar and limestone. In some parts of the building sculptured stones of the Sassanide period have been used. This Eilkhani structure was utilized till the late Teimoorid period, but in later periods it became deserted and ruined.