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 this water trail reach Lake Superior, while the downstream traveler could use it to go southwest to the Gulf of Mexico, unhindered by portages, by using the St. Croix and Mississippi rivers. This waterway was also an important route in the Wisconsin fur trade, particularly when the French War with the Fox Indians closed the more southern routes. In the nineteenth century, spurred by the prospect of lucrative shipping on the Great Lakes and exploitation of the iron ore industry, businessmen from Chicago and St. Paul, Minnesota laid claim to the site which became the city of Superior. They planned