High Quality Content by WIKIPEDIA articles! The Twin Ports of Duluth, Minnesota and Superior, Wisconsin are located at the western part of Lake Superior (the westernmost of North America's Great Lakes) and together are considered the largest freshwater port in the world. They are twin cities and seaports, connected to the Atlantic Ocean through the Great Lakes and the St. Lawrence Seaway. The Twin Ports are at the core of the U.S. Census Bureau's "Duluth-Superior Metropolitan Statistical Area", which includes all of Wisconsin's Douglas County, and Minnesota's Carlton and St. Louis counties. With a 2000 census population of 275,486, the Duluth-Superior MSA ranked as the 163rd largest metropolitan area in the United States.