Mystery Cave is the longest cave in Minnesota, with more than 13 miles of passages, and it is the centerpiece of Forestville/Mystery Cave State Park in Fillmore County, between Spring Valley and Preston in southeastern Minnesota. The Minnesota Department of Natural Resources runs the tours. The one-hour scenic tour is the best overall experience, showing stalactites, stalagmites, flowstone and underground pools along a lit route of about three-quarters of a mile of paved trails and bridges that are wheelchair accessible. For adventurous visitors, a 2.5-hour advanced education tour adds a surface visit to a scientific and natural area, and a 4-hour wild caving tour requires crawling and is limited to small groups and older teens and adults. The cave stays at 48 degrees Fahrenheit year-round. Around the cave, the park offers hiking and horse trails, trout fishing, birding and camping, and the Minnesota Historical Society manages the historic Forestville site. It makes a satisfying day trip of about an hour from Rochester, particularly on hot days when the cave is cool.
Planning
Tours run on a seasonal calendar, typically from mid-spring to mid-autumn, with scenic tours daily in the warmer months and advanced and wild tours on weekends. Reserve online or by phone, since scenic tours are limited in size, and arrive at least 30 minutes early because late arrivals are not refunded.
Wear warm clothing and sturdy shoes, as the cave is cool and damp. There are no restrooms underground. Taxes and fees may apply, and a state park pass or vehicle permit may be needed for the park. Check the state park website, because the schedule changes by year.
What to expect
A guided walk through chambers with dripping formations and clear pools, lit with modern lighting and followed by a return to the surface. Guides explain the geology of the karst landscape, where water dissolved limestone over millions of years. Flash photography is allowed, which helps you capture the formations. Above ground, the park has quiet trails and a visitor center. Families with children over five will enjoy the scenic tour.
Making the most of it
Combine the cave with a bike ride on the Root River State Trail from nearby Preston or Fountain, a visit to historic Forestville and a stop in Lanesboro. Bring a jacket even in summer. Trout anglers should check regulations and licenses. If you want a different style of cave, Niagara Cave in Harmony is about 20 minutes southeast. Plan lunch in Spring Valley or Preston, where small cafes serve local fare.
Good to know
Southeastern Minnesota belongs to the Driftless Area, a region the glaciers bypassed, which is why its karst caves, sinkholes and springs are so well preserved. Visitors often combine the cave with the Forestville historic site run by the Minnesota Historical Society. Because the cave tours are limited in size, weekends and holiday periods fill early, so book as soon as you know your dates.
The park also has camper cabins and campsites if you want to make it an overnight trip. Keep in mind that the cave route includes stairs and cool, damp air, so bring a jacket and shoes with good grip.
What to expect
The experience
A guided cave tour in a state park, with a one-hour scenic route and optional longer tours.
Best time
Summer, when the cave offers cool relief, within the mid-spring to mid-autumn season.
How long
One hour for the scenic tour, plus the drive.
Tips
Reserve ahead, arrive 30 minutes early and bring a warm layer.
Quick picks
- Best for
- Families and geology fans who want a cool, easy underground outing.
- Families
- Suitable for children old enough to follow a guided tour.
- Couples
- A shared adventure with a countryside drive.
- Pair with
- Lanesboro and the Root River State Trail.
- Time needed
- Half a day.
Good questions
How long is the scenic tour?+
About one hour.
How cold is the cave?+
It stays at 48 degrees Fahrenheit year-round.
Is it accessible?+
The scenic and advanced tours are accessible underground along about three-quarters of a mile of paved trail and bridges.
How early should I arrive?+
At least 30 minutes before your tour, since late arrivals are not refunded.
Are there other tours?+
Yes. A 2.5-hour advanced tour and a 4-hour wild caving tour are offered on a limited schedule.