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 Maritime Visitor Center of upper Great Lakes commercial shipping and the Aerial Lift Bridge. Many visitors particularly enjoy the three historically accurate replica cabins and a pilothouse from typical ships which plowed the waves of Lake Superior in years past. A three-story steam engine, 50 scale models and many interactive displays are available for visitors to explore. Thousand-foot-long freighters pass within 200 feet of the building, underneath the Aerial Lift Bridge, which lifts up to allow them to pass through. Lake Superior Maritime Visitor Center The Lake Superior Maritime Visitor Center is a museum in Duluth, Minnesota, operated by the United States Army