Quhistan (Persian:قهستان) orKohistan (کهستان, "mountainous land") was a region of medieval Persia, essentially the southern part ofKhurasan. Its boundaries appear to have been south of Khorasan to north, Yazd to West, Sistan to South, Afghanistan to East. Quhistan was a province in old days with a rich history in Persian literature, art and science. Notable historical towns include Tun (modern-dayFerdows),Qa'in,Gunabad,Tabas,Birjand,Turshez (modern-dayKashmar),Khwaf,Taybad, and Zawah (modern-dayTorbat-e Heydarieh).It is home to famous castles. Safron, berberies (Zereshk) and jujube (Annab) are among the famous agricultural products that are exclusively produced in Ghohestan. HakimNezari Ghohestani,[1]Sima Bina[2][circular reference] and Professor Reza Ghohestani[3] are among famous people who are originally from Ghohestan.
Dagestan in theNorth Caucasus was previously and originally named"Quhistan", which has the same meaning asDagestan:dağ andkuh are theTurkic and Persian words for "mountain", respectively.-istan is Persian suffix meaning "land [of]".