Ubsunur Hollow

Ubsunur Hollow (also spelled Uvs Lake Basin; Mongolian: Увс нуурын хотгор) is a fragile mountain endorheic basin or depression located on the territorial border of Mongolia and the Republic of Tuva in the Russian Federation, named after Uvs Lake, a large, shallow and very saline lake in the basin's center. Several smaller lakes are scattered throughout. It is part of a combination of raised lands and depressions located throughout the Tannu-Ola and Altai mountainous regions. Here, the world's most northern desert meets the northern hemisphere's most southern tundra zone. The Ubsunur Hollow was inscribed on the World Heritage Site in 2003.

The total area of Uvs Lake drainage basin is 70,000 km². The greater part of it lies in Mongolia (Khövsgöl, Zavkhan and Uvs Provinces), and the northern part in Russia (Tuva).