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
Geology of Minnesota and subsections. "Northeastern Minnesota" is an irregularly-shaped region composed of the northeasternmost part of the state north of Lake Superior, the area around Jay Cooke State Park and the Nemadji River basin southwest of Duluth, and much of the area east of U.S. Highway 53 that runs between Duluth and International Falls. Excluded are parts of the beds of glacial lakes Agassiz and Upham, the latter now occupied by the upper valley of the Saint Louis River and its tributary the Cloquet. This area is coextensive with the Northern Superior Uplands Section of the Laurentian Mixed Forest. Known as the