Uvs Lake is a highly saline lake in an endorheic basin—Uvs Nuur Basin, primarily in Mongolia with a smaller part in Russia. It is the largest lake in Mongolia by surface area, covering 3,350 km2 at 759 m above sea level. The northeastern tip of the lake is situated in the Tuva Republic of the Russian Federation. The largest settlement near the lake is Ulaangom. This shallow and very saline body of water is a remainder of a huge saline sea which covered a much larger area several thousand years ago.

Uvs Lake Basin is an endorheic basin located on the territorial border of Mongolia and Tuva, a republic of the Russian Federation. The basin is part of the Central Asian Internal Drainage Basin and is named after Uvs Lake, a large saline lake situated in the western part of its drainage basin, and is one of the last remnants of the mammoth steppes. Uvs Lake is a shallow lake with an area of 3,350 km2 (1,290 sq mi). Its entire basin, which includes several smaller lakes, is 70,000 km2 (27,000 sq mi).