An Engineering Wonder, City of Duluth, Minnesota, US

Duluth is a seaport city in the State of Minnesota , United States. The city is considered to be an Engineering Wonder due to its Aerial Lift Bridge. It is the 5th largest city in the state of Minnesota. It is also the second-largest city on Lake Superior's shores, after Thunder Bay, Ontario.The city has 2 sea ports and also the starting point for the vehicle trips.