Split Rock Lighthouse is less than an hour up highway 61 along Lake Superior and is a MUST. There are also great hiking trails there, and elsewhere along the highway. You'll see plenty of cars parked along the side of the road to indicate a trailhead.
And I forgot to mention Gooseberry Falls which is very close to Split Rock. Beautiful place to hike and see the waters rushing under the road and into Lake Superior. Be sure to take the trail inland, as many other people will also be doing. The scenery is gorgeous and it'll quickly show you why people love the North Shore, as it's called. Two Harbors is the only town along the way to Split Rock worth noting, but it's a cute stopping point for browsing a shop or two and to grab food or coffee. FYI, I went to college at MTSU in Murfreesboro, and my brother and his family live in Louisville. I've been up here for 35 years though. It's a really great area.