A diatom Cyclotella ocellata from the Lake Hovsgol, Lake Khövsgöl or Hövsgöl Nuur in Mongolia.

The lake Hövsgöl is several million years old. Glaciers probably never reached it during the last Ice Age.

The lake is 136 km long and between 20-40 km wide and its deepest point is at 262 m. It contains almost 70% of the surface freshwater of Mongolia. The area supports low levels of human activity and the lake itself is remarkably preserved.