The World's Largest Freshwater Lakes

Superior is so big it generates its own weather. Cold air passing over the warmer lake picks up moisture and dumps it as "lake-effect snow" on the downwind shore — some spots in Michigan's Upper Peninsula regularly get over 200 inches of snow a year because of it.

The lake holds about 10% of the world's surface freshwater, and its water is cold enough year-round that it doesn't fully "turn over" the way warmer lakes do. Shipwrecks at the bottom are remarkably preserved — Superior's cold, low-bacteria water essentially mummifies whatever sinks into it. The wreck of the Edmund Fitzgerald, which sank in a 1975 storm, still sits on the bottom largely intact.

Victoria is the world's largest tropical lake and the primary source of the White Nile — the river that flows north all the way through Sudan and Egypt before emptying into the Mediterranean. It sits at about 1,135 meters above sea level on a high plateau shared by three countries.

The lake was named by British explorer John Hanning Speke in 1858, who was the first European to see it. He named it after Queen Victoria. The local name, used for centuries before that, was Nalubaale. The lake supports one of the world's largest freshwater fishing industries, but that industry has been complicated by the introduction of Nile perch in the 1950s, which wiped out hundreds of native cichlid species.

Baikal is the one that breaks your brain a little once you sit with the numbers. It's about 25 million years old — ancient enough that it predates most of the mountain ranges around it. It sits in a rift valley that's still actively spreading, which means the lake is slowly getting deeper every year.

It's home to around 3,700 species of plants and animals, about two-thirds of which exist nowhere else on Earth. The Baikal seal (nerpa) is the world's only exclusively freshwater seal species — nobody fully knows how it got there, since the lake has no direct connection to any ocean. The leading theory is that ancestors migrated through an ancient river system from the Arctic during the last ice age.

In winter, the lake freezes over and the ice becomes thick enough to drive vehicles across. The Trans-Siberian Railway originally ran across the ice in winter before a proper rail line was built around the southern shore. Locals call Baikal "the sea."

Tanganyika is the world's longest freshwater lake — it stretches 676 kilometers from north to south, which is about the same distance as driving from New York City to Charlotte, North Carolina. Like Baikal, it formed in a rift valley and it's genuinely ancient, somewhere between 9 and 12 million years old.

It borders four countries and has its own sardine fishery that feeds millions of people across the region. The lake was "discovered" by Europeans in 1858 by Burton and Speke, the same expedition that later reached Lake Victoria. Speke spent most of the journey ill and didn't recognize what they were looking at until they were already there.

Michigan is the only one of the Great Lakes entirely within the United States. It connects to Lake Huron at the Straits of Mackinac — hydrologically, they're actually considered a single lake (Michigan-Huron) by some geographers, which would make it the largest freshwater lake in the world by surface area. The debate mostly comes down to whether a wide strait counts as a connection or a separation.

These two lakes sit in Canada's Northwest Territories and are among the least-visited large lakes on Earth. Great Bear Lake is the largest lake entirely within Canada, and it sits almost directly on the Arctic Circle — it's frozen for eight months of the year. Great Slave Lake is the deepest lake in North America at 614 meters, which surprises most people who assume that title goes to one of the more famous Great Lakes.

Lake Malawi is sometimes called "the calendar lake" because it's roughly 365 miles long and 52 miles wide — though this is more fun fact than precise measurement. It contains more species of fish than any other lake on Earth: over 1,000 species of cichlids, most of them found nowhere else. The lake is essentially an evolutionary laboratory that biologists have been studying for decades.