Duluth, Minnesota Lakes Waterway and the Saint Lawrence Seaway. Duluth forms a metropolitan area with neighboring Superior, Wisconsin, called the Twin Ports. The cities share the Duluth–Superior harbor and together are the Great Lakes' largest port, transporting coal, iron ore (taconite), and grain. A tourist destination for the Midwest, Duluth features the United States' only all-freshwater aquarium, the Great Lakes Aquarium; the Aerial Lift Bridge, which spans the Duluth Ship Canal into the Duluth–Superior Harbor; and Minnesota Point (known locally as Park Point), the world's longest freshwater baymouth bar, spanning . The city is also the starting point for vehicle trips along
Lake Superior during the 17th century referred to their discovery as "le lac supérieur". Properly translated, the expression means "Upper Lake," that is, the lake above Lake Huron. The lake was also called "Lac Tracy" (named for Alexandre de Prouville de Tracy) by 17th century Jesuit missionaries. The British, upon taking control of the region from the French in the 1760s following the French and Indian War, anglicized the lake's name to "Superior", "on account of its being superior in magnitude to any of the lakes on that vast continent." Lake Superior empties into Lake Huron via the St. Marys River and