Quhistan
Introduction '''Quhistan''' () or '''Kohistan''' (, "mountainous land") was a region of medieval Persia, essentially the southern part of Khurasan. 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-day Ferdows), Qa'in, Gunabad, Tabas, Birjand, Turshez (modern-day Kashmar), Khwaf, Taybad, and Zawah (modern-day Torbat-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. Hakim Nezari Ghohestani, Sima Bina and Professor Reza Ghohestani are among famous people who are originally from Ghohestan.Dagestan in the North Caucasus was previously and originally named ''"Quhistan"'', which has the same meaning as ''Dagestan'': ''dağ'' and ''kuh'' are the Turkic and Persian words for "mountain", respectively. ''-istan'' is Persian suffix meaning "land of".
See also *Nizari Ismaili state
References
Sources * C. Edmund Bosworth. "The Ismai'ilis of Quhistan" in Farhad Daftary. ''Medieval Isma'ili History and Thought''.