Buir Lake

Buir Lake (Buir Nuur) is the largest lake in eastern Mongolia, a freshwater lake of roughly 610 km² on the border with China, whose northern tip lies in Inner Mongolia. It is about 40 km long and 20 km wide but fairly shallow, with an average depth usually given as 6 to 10 m. The Khalkh River enters through a marshy delta, and the Orshuun River drains the lake north into China's Hulun Nur. The Khalkhin Gol battlefields of 1939 lie just to the east.

Shore, delta and steppe

The Khalkh delta is a mix of wet grassland, reed beds and willow thickets, while behind the open shore are sand dunes with small lakes and wide grassland steppe. The lake and its wetlands have been a Ramsar Wetland of International Importance since 2004. Threatened birds recorded here include swan goose, white-naped crane, Oriental stork, relict gull and Pallas's fish eagle, and in migration the lake holds large numbers of great crested grebes, great cormorants, ruddy shelducks and northern lapwings. Surveys list more than 30 fish species, among them common carp, pike, Amur catfish, Amur ide and Mongolian culter.

Seasons and timing

Buir is frozen from about November to the end of April, so the open-water season runs from May to October. June to August is the warmest period, while May and September are best for migrating birds. Expect mosquitoes near the reeds in summer and strong wind on the open shore.

A border lake

Mongolian border guards patrol the lake, so keep your permit and passport with you, stay away from the boundary and ask before photographing posts or patrols. Check current fishing rules locally before you cast. Camp on firm ground above the shore, keep vehicles on existing tracks to protect the grassland, and take all rubbish away with you.