Mazar Tagh is the site of a ruined hill fort in the middle of the Taklamakan desert, dating from the time of the Tibetan Empire.

Like the Miran fort site, its excavation has yielded hundreds of military documents from the 8th and 9th century, which are among the earliest surviving Tibetan manuscripts, and vital sources for understanding the early history of Tibet.

[1] The site is now located north of the modern city of Hotan in the Xinjiang Autonomous Region of the People's Republic of China.

As well as excavating the fort, Stein discovered a large refuse heap on the north and northeast slopes of the hill, which contained hundreds of discarded Tibetan military documents on paper and wood.

[2] Stein also discovered other kinds of artefact, though in much smaller number, including arrows, sheathes, shoes, dice, a comb and a pen.