It's. Looking for something to do this summer? Try the Great Lakes. Hear about it at urban legends and stranger truths the Great Lakes of North America span 750 miles from east to west from the largest freshwater system on earth. Here are a few facts about the five lakes. First, Lake Superior is the biggest and the deepest by far. Lake Superior, the world's largest freshwater lake, straddles the US. Can at a border and touches Minnesota, Wisconsin and Michigan