Buir nuur

Buir Lake
Satellite image of Buir Lake
Location	Dornod Province, Mongolia and Hulunbei'er, China
Coordinates	47°48′N 117°40′E / 47.800°N 117.667°E / 47.800; 117.667Coordinates: 47°48′N 117°40′E / 47.800°N 117.667°E / 47.800; 117.667
Ramsar Wetland
Designated	22 March 2004

Buir Lake (Mongolian: Буйр нуур; Chinese: 贝尔湖; pinyin: Bèi'ěr Hú) is a freshwater lake that straddles the border between Mongolia and China. It lies within the Buir Lake Depression. The Chinese city of Hulunbuir is named after both this lake and Hulun Lake, which lies entirely on the Chinese side of the border in Inner Mongolia.

In 1388, Ming forces under Lan Yu won a major victory over the Northern Yuan Dynasty on the Buir Lake region. Northern Yuan ruler Tögüs Temür tried to escape but was killed shortly afterwards.