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
Duluth, Minnesota is credited with the European discovery of Lake Superior before 1620. Pierre-Esprit Radisson and Médard des Groseilliers explored the Duluth area, Fond du Lac (Bottom of the Lake) in 1654 and again in 1660. The French soon established fur posts near Duluth and in the far north where Grand Portage became a major trading center. The French explorer Daniel Greysolon, Sieur du Lhut, whose name is sometimes anglicized as "DuLuth", explored the Saint Louis River in 1679. After 1792 and the independence of the United States, the North West Company established several posts on Minnesota rivers and lakes, and in