There are two cave systems in southern MN’s rocky bluff country: the privately owned “Niagara Cave,” named for an underground waterfall, and the state-owned cave system “Mystery Caves.” The latter of the two has 13 miles of developed tunnels, but may span up to 50 miles or more. The cave system is operated by Forestville-Mystery Caves State Park under the Department of Natural Resources, and there are several different difficulty level tours available.
Another geologic wonder of MN, found in the amazingly beautiful Whitewater State Park, is Chimney Rock. Whitewater sits in the absolute heart of bluff country, northeast of Rochester about 30 miles, and the hikes and scenic overlooks are amazing. One of the hikes takes you up to an overlook on the east side of the park. On the way up, you will pass Chimney Rock. A 40-foot tall limestone rock column that has been worn away so you can actually climb around in it.
Five-hundred-million years ago, a shallow sea covered much of North America, specifically this portion of southeastern Minnesota. Sediment accumulated which later turned into this rock hundreds of feet thick. The sea eventually retreated and later on, an ice age came through, causing glaciers to sculpt the area’s bluffs and rock outcrops. Chimney rock is a great example of the ancient history of this area.
While in the area: Coyote Point and Eagle Point are both pretty good hikes in this park too, or try some fishing in the trout-stocked Whitewater River. Or, swing up to Elba, MN and climb to the top of the Elba Fire Tower for spectacular panaromic views of the area.