English: An astronaut on the International Space Station captured this photograph of the southern tip of Lake Khuvsgul (also known as Lake Hovsgol or Hovsgol Nuur) in north central Mongolia. Referred to as the “younger sister” of Lake Baikal, Khuvsgul is approximately 137 kilometers (85 miles) long and is the largest fresh water lake in Mongolia by volume. (Note that north is to the lower right in this image.)

Several rivers and streams flow down from higher elevations (including the Sayan Mountains) and into Lake Khuvsgul. The Egiin River is the only outflow, ultimately carrying water to Lake Baikal through the Selenga River. Together, the two lakes hold more than 20 percent of Earth’s fresh surface water.

The different shades of blue indicate different water depths—the deeper the blue, the deeper the water. Boreal forests (also referred to as taiga) cover the mountain slopes, while several streams cut through the forest and flow into the lake. Hatgal, a village with less than 4,000 inhabitants, sits on the lake shore and makes up most of the population in Khuvsgul Province. The lake and its surroundings are part of 11,803 square kilometers (4,557 square miles) of protected land designated as Lake Hovsgol National Park.