In western Mongolia, braided streams of sand dunes stretch east-west across the arid landscape. One ribbon of sand, spanning roughly 200 kilometers, extends from an area south of Khyargas Lake in the west to a smaller lake, Telmen Nuur, in the east. In between, sand dunes march past Har Nuur, or "Black Lake."
Har Nuur sits in the Valley of Lakes of western Mongolia. Bordered by multiple mountain ranges, the Valley of Lakes hosts remnant basins of larger ancient lakes, dune fields, and salt marshes. Har Nuur, like other lakes in the region, is a closed-basin lake fed by precipitation.