Interstate State Park MN

It’s a tale of two states at Interstate State Park, named the same thing on both the Wisconsin and Minnesota sides. It was the first park in the country to span two states (you’ll need different vehicle permits to pass between the two), and attracts geologists from all over the world for its insane rock formations. This park is home to the Bottomless Pit, the deepest explored pothole in the world at 60 feet deep, as well as several other hilariously named dents in the bedrock. The St. Croix River, a deep basalt gorge filled with glacial potholes, hosts scenic boat cruises if you want to relax, or you can rent a canoe or kayak for the day. Swimming there might be a little too dicey with the strong currents, but the river walls provide killer climbs for those interested (just make sure you sign the waiver in the park office before you chalk up).