Sanjan is an ancient city on the southern edge of the Kara-kum Desert, in the vicinity of the historically eminent oasis-city of Merv.
Topographically, Sanjan is located in the Greater Khorasan region of Central Asia.
Together with Merv, Sanjan was an important stopping place and center of trade on the southern route of the Silk Road.
As a site in the Bactria-Margiana Archaeological Complex, Sanjan is subject to the hypothesis that the Indo-Iranians, a major branch that split off from the Proto-Indo-Europeans, originated there.
(see also: BMAC:Indo-Iranian hypothesis) According to the Qissa-i Sanjan, an epic poem from around 1600, the Zoroastrians who fled to the Indian subcontinent in the 8th or 9th century, to escape religious persecution from Islamic invaders, established the settlement of Sanjan (Gujarat).