In the middle of our Cave of the Mounds tour, the guide asked if we wanted to experience what "total darkness" was like.
Of course, the answer was yes.
My 6-year-old nervously grabbed my hand. Then the guide switched off the lights and the cave went completely black. It wasn't just dark. It was a disorienting, can't-see-your-hand-in-front-of-your-face dark.
It was freaky cool, just like the cave itself, and one of the highlights of our visit.
The Midwest is home to dozens of interesting caves. Some, like Cave of the Mounds, are "show caves" complete with lighting, paved paths and guided tours. Others are "wild caves," where spelunkers squeeze through tiny dark spaces and rappel down pits.
For families with young children, show caves are the safest bet. The kids will learn a little bit about history (how are caves formed?) science (know the difference between stalagmites and stalactites?) and will be captivated by what they're seeing (cool!).
Just remember to bring a jacket, because caves are always a chilly 50 degrees inside.
Some of the most popular show caves in the Midwest include:
Cave of the Mounds Blue Mounds, Wis. caveofthemounds.com
A short drive from Madison, tours of this U.S. Natural Landmark start with a short movie on the cave's history and then a 45-minute walk past many large and tiny spaces filled with colorful stalagmite and stalactite formations. If you're invited to experience total darkness, do it!
Outside the cave, walk the landscaped grounds or let the kids "mine" for gemstones and fossils. It involves buying bags of treasure-filled sand in the gift shop and letting them sift it in a moving water trough. They can then identify what they found and take them home as souvenirs. Or, save money by letting them put on plastic hard hats and dig for the same gems and fossils in the free, giant sandbox (they just can't keep them).
Marengo Cave Marengo, Ind. marengocave.com
Tours of this massive, southern Indiana cave have been given for more than 125 years. Visitors get to pick from two separate paths, the 40-minute Crystal Palace tour, and the 70-minute Dripstone Trail. Like Cave of the Mounds, the guide will likely offer the "total darkness" experience, and above ground, there's gemstone and fossil mining for an extra fee. However, the Crystal Palace tour has an in-cave movie on the cave's history. Our tour was filled with oohs and aahs, especially when we entered the darkened cave and the guide dramatically flipped on the lights to reveal an expansive cave view.
Niagara Cave Harmony, Minn. niagaracave.com
The interior of this cave is so scenic, weddings are held here. So many weddings, there's even a wedding chapel built inside.
Aside from the interesting stalagmite and stalactite formations, the underground sights include a wishing well, an echo chamber, a waterfall, and a Stalactite Room with a rainbow of rock formations. Located in southeast Minnesota, on the Iowa border, the cave is only open from May through September.
Meramac Caverns Stanton, Mo. americascave.com
The state of Missouri has nearly 6,000 caves. But this one, outside St. Louis, is one of its most popular. It has some interesting history behind it too: Jesse James and his gang used it for a post-heist hideout, slaves traveling north on the Underground Railroad stayed here, and before that, local Indian tribes use it as shelter. Meramec Caverns' 26 miles of underground passages holds many notable formations, including an incredible 70-million-year-old speleothem called "The Stage Curtain," which is the largest single cave formation in the world, measuring 70 feet high, 60 feet wide, and 35 feet thick.
Mammoth Cave Mammoth Cave National Park, Ky. nps.gov/maca
The granddaddy of all caves, owned by the National Park Service and named a World Heritage Site, is the longest cave in the world with 392 miles of passages. As a result, there are more than a dozen tours you can take, including some that involve bus rides. The features are too long to list, but by all accounts, it's an amazing site to see and well worth the trip to central Kentucky.
Ohio Caverns West Liberty, Ohio ohiocaverns.com
One of the smaller show caves in the Midwest, the Ohio Caverns are filled with colorful, interesting formations and large open chambers covered in stalagmites and stalactites. Its crown jewel is its 200,000-year-old, 5-foot-tall, pure white crystal stalactite -- one of the largest of its kind anywhere. The caverns also provide "mining" for kids and a 35-acre above-ground park and playground to help make the visit a whole-day outing.
Spook Cave McGregor, Iowa spookcave.com
Tours of this flooded cave, near the Iowa-Wisconsin border, are done in a boat. While it's touristy, and water from the top of the cave sometimes drips on the passengers, it's a unique way to tour a cave. Watch out, because at several points during the 35-minute tour, you'll have to duck your head down to avoid getting conked by the rocks. The Spook Cave management won't disclose why it's called a spook cave -- you have to take the tour to find the answer. Camping and cabins are also on the property if you want to spend the night or weekend.