Although they don’t have salt water, the Great Lakes are vast, and can feel like small oceans. This connected series of lakes, Superior, Michigan, Huron, Erie, and Ontario, are the largest surface freshwater system on earth and account for 21 percent of the world’s supply. They shape the north coast of the United States, bordering eight states and the Canadian province of Ontario, for a total of 10,200 miles of coastline. That surpasses the East Coast of the U.S. (2,069 miles)!