Lake Superior is the largest freshwater lake in the world by surface area and the third-largest by volume, holding 10% of the world's surface fresh water.

Lake Superior is the deepest and coldest of the Great Lakes, with a maximum depth of 1,333 feet (406 meters). This point, known as the "deepest spot," is located roughly 40 miles north of Munising, Michigan. To put that in perspective, the lake is deep enough to submerge the Empire State Building with room to spare. The average depth of the lake is about 483 feet (147 meters). Because of its immense volume—holding about 2,900 cubic miles of water—it contains enough water to fill all the other Great Lakes plus three additional Lake Eries. The sheer depth of the lake contributes to its legendary "unpredictable" nature; the water stays a constant, bone-chilling 39°F (4°C) at its deepest levels year-round. This extreme depth and cold have also made it a famous "underwater museum," as the cold, fresh water preserves shipwrecks in near-perfect condition for decades, or even centuries, at the bottom of the basin.