The Great Lakes are a prominent feature of the North American landscape, but Russia holds the distinction of having the "World's Great Lake." Called the "Pearl of Siberia" or the "Sacred Sea" by locals, Lake Baikal is the world's deepest and largest lake by volume. It has a surface area of 12,162 sq miles (31,500 sq km), a maximum depth of 5,370 ft (1,637 m), or slightly more than 1 mile, an average depth of 2,428 ft (740 m), and a volume of 30,061 cu yd (23,000 cum). It thus contains more water than the combined volume of all of the North American Great Lakes—20 percent of the world's fresh water (and 80 percent of the fresh water of the former Soviet Union).

Lake Baikal is located in Russia in south-central Siberia near the northern border of Mongolia. Scientists estimate that the lake was formed 25 million years ago by tectonic (earthquake) displacement, creating a crescent-shaped, steep-walled...