Lake Merzbacher, Glacial lake in Tien Shan mountains, Kyrgyzstan

Lake Merzbacher is a glacial lake in the Tien Shan mountains of eastern Kyrgyzstan, lying between the north and south Engilchek glaciers. It sits behind a dam of ice and rock debris, and its water level changes through the year as the dam holds or releases the meltwater.

The lake was named after Gottfried Merzbacher, a German explorer who led an expedition to the area in 1903. His account of the region brought attention to the lake and its unusual cycle, which has been observed by travelers and scientists ever since.

Local herders and travelers know the lake by its nickname, the Disappearing Lake, because its sudden emptying is a familiar event in the valley. People downstream watch the water level closely in summer, and the lake's behavior is part of the seasonal rhythm of life in the Engilchek area.

Reaching the lake requires a long journey from the nearest road, usually with a guide and pack animals, and the terrain is rough and remote. Visitors should plan for changeable mountain weather and allow extra days, as the lake can be full or nearly empty depending on the season.

When the ice dam breaks, the lake can drain in just three days, with water rushing out at rates up to 1000 cubic meters per second. This sudden release often causes floods downstream, damaging roads and infrastructure far from the lake itself.