Semnani

The Semnanis are a Caspian Iranian people living on the arid northern fringe of the central plateau, in the old region of Qumis around Semnan, Damghan and Sorkheh. Their ancestors moved inland from the southern Caspian shore and intermarried with plateau tribes. Their Semnani tongues form a Northwestern Iranian group close to Gilaki and Zaza, preserving features of ancient Median.

Their land held Hecatompylos, a capital of the Parthian Empire by 200 BC, whose ruins near Damghan were abandoned after the great earthquake of 856. For roughly a thousand years the Semnanis have watered desert alluvial fans with stone channels and underground aqueducts, dividing snowmelt through a splitter channel known as the Parö under a registrar called the engarnevis.