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
Superior, Wisconsin by Saint Louis, Superior, and Allouez bays, the city is framed by two rivers: the Nemadji and the Saint Louis. Superior and the neighboring city across the bay, Duluth, Minnesota, form a single metropolitan area called the Twin Ports. They share a harbor that is one of the most important ports on the Great Lakes. Both cities feature museum ships ("SS William A. Irvin" in Duluth and "" in Superior) devoted to the local maritime heritage. Superior was the final port of call for the "Edmund Fitzgerald" before its sinking in 1975. The first-known inhabitants of what is now Douglas