▁city ▁run ▁under ground , ▁and ▁it ▁is ▁said ▁that ▁an ▁Arab ▁who ▁was ▁off ended ▁by ▁the ▁people ▁of ▁N ey sh ab oor ▁has ▁compla ined ▁that ; ▁what ▁a ▁beautiful ▁city ▁N ey sh ab oor ▁could ▁have ▁become ▁if ▁its ▁q an ats ▁would ▁have ▁flow ed ▁on ▁the ▁ground ▁surface ▁and ▁instead ▁its ▁people ▁would ▁have ▁been ▁under ground ”. ▁These ▁documents ▁all ▁cert ify ▁the ▁importance ▁of ▁q an ats ▁during ▁the ▁Islam ic ▁history ▁within ▁the ▁cultural ▁territ ories ▁of ▁Iran . ▁ ▁In ▁the ▁ 1 3 th ▁century , ▁the ▁invasion ▁of ▁Iran ▁by ▁Mong ol ian ▁tribes ▁reduced ▁many ▁q an ats ▁and ▁ir rig ation ▁systems ▁to ▁ru in , ▁and ▁many ▁q an ats ▁were ▁desert ed ▁and ▁d ried ▁up . ▁Later , ▁in ▁the ▁era ▁of ▁the ▁Il k han id ▁dynast y ▁especially ▁at ▁the ▁time ▁of ▁Gh az an ▁Khan ▁and ▁his ▁Pers ian ▁minister ▁R ash id ▁al - D in ▁F az l - Al lah , ▁some ▁measures ▁were ▁taken ▁to ▁rev ive ▁the ▁q an ats ▁and ▁ir rig ation ▁systems . ▁There ▁is ▁a ▁▁ 1 4 th - century ▁book ▁entitled ▁" Al - V agh fi ya ▁Al - R ash idi ya " ▁( R ash id ' s ▁De eds ▁of ▁End ow ment ) ▁that ▁names ▁all ▁the ▁properties ▁located ▁in ▁Y az d , ▁Sh ira z , ▁Mar ag he , ▁Tab riz , ▁Is