Planning a summer road-trip with your family?  You could spend a day at Valleyfair, or a long weekend in Duluth, but you've probably already done those things.  If you're looking for something new and unique you should check out Soudan Underground Mine State Park. It's located in the Lake Vermilion area and there is camping available nearby.

Popular Mechanics ranks it as Minnesota's top summer road-trip destination. The Soudan Mine was Minnesota's first working iron ore mine and was operational until 1962. Each day from Memorial Day to Labor Day they give tours. You'll have to wear a hard-hat as you enter the "train" that'll take you three-quarters of a mile underground. Check out the video above for a preview of the tour and click here to learn more about the Soudan Underground Mine.