Minnesota and western Wisconsin are home to a surprising number of caves. Some are only accessible to experienced cavers, but there are a number of fascinating underground caves around the Twin Cities that are open to the public. On your visit, you may see fossils, exquisite underground rock and crystal formation, waterfalls, pools, and be introduced to the unique geology of the area.
The temperature in a cave is usually fairly stable, and somewhere around 50F, even when the temperature above ground is nearing 100F. You'll want to bring a sweater. Good walking shoes are also recommended. Most people can take a cave tour - many are ADA accessible, and suitable for all ages.
Here's a list of caves, mines, and other underground attractions around Minneapolis and St. Paul, in Minnesota and western Wisconsin, that are open to visitors.