Lake Superior is the largest body of fresh water in the world by surface area.

H.O.M.E.S.: Huron, Ontario, Michigan, Erie, and Superior. That’s the order in which American schoolchildren learn to recall the Great Lakes. But if you were to remember the sea-sized lakes according to their size, Lake Superior would come first. At 31,700 square miles — the approximate size of the state of South Carolina — Lake Superior is the largest of the Great Lakes. It also happens to be the world’s largest freshwater lake by surface area, holding more than 10% of the planet’s surface fresh water. (Close to 70% of Earth’s remaining fresh water is inaccessible, stored frozen in glaciers, ice caps, and permafrost.) While each of the Great Lakes is massive, Lake Superior’s size is staggering. Reaching a maximum depth of 406 meters (about 1,332 feet), Superior is the coldest and deepest of its sister lakes. It contains about 3 quadrillion gallons of water — half of the water in all the Great Lakes. And while water from Lake Superior feeds into Lake Huron, scientists believe that Superior retains water so well that it would take 191 years to empty if it never received another drop.