The inland lake Uws Lake (Uvs Lake) is about 25 kilometers from Ulaangom. It is drained and saline, but has only half as much salt as the sea. With an area of 3350 square kilometers and a diameter of 84 kilometers, it is the largest lake in Mongolia, about five times the size of Lake Constance. It measures 26 meters at its lowest point and its water level is 760 meters above sea level. Its dimensions are best seen on the south bank – you can only find places to swim there, but only when you have waded through damp places. In winter it can get cold here down to minus 57 ° C. Then the lake freezes over despite its salinity. It is fed by around 200 rivers and streams whose deltas form wetlands, including the Tes River. Delta is about 40 kilometers wide. Many migratory birds can be found here, the nearest ocean is 3000 kilometers away. The whole area has been protected since 1994 and has been a UNESCO World Heritage site since 2003.