Cascade State Park
The north shore has no shortage of waterfalls, but Cascade Falls ranks as one of the best. It's a quick walk to the falls from the parking area, and worth a stop. Even if you don't plan on spending the day hiking.
If you do spend the day hiking at Cascade you'll be treated to one of the best overlooks on Minnesota's north shore! The overlook at Lookout Mountain is a steep hike, but the view is priceless.