Duluth is a port city in the U.S. state of Minnesota and the county seat of St. Louis County. The city is named for Daniel Greysolon, Sieur du Lhut, the first known European explorer of the area. As a tourist destination for the Midwest, Duluth features America's only all-freshwater aquarium, the Great Lakes Aquarium, the Aerial Lift Bridge which spans the short canal into Duluth's harbor, "Park Point", the world's longest freshwater sandbar, spanning 6 miles, and is a launching point for the North Shore.