The Midwest has a reputation for being more or less “flyover states.” The overwhelmingly flat landscape of our country’s central region doesn’t get much love, but if you take a peek underneath you’ll be fascinated by what you find. The Midwest has a large concentration of underground cave systems just waiting to be explored.

Mammoth Caves National Park

Mammoth Cave, Kentucky

Mammoth Cave National Park is often considered the granddaddy of cave systems in the U.S. The World Heritage site boasts the largest underground network on Earth with over 400 miles of explored passages. With so much available space, there are over a dozen tours available for the less adventurous, and plenty of options for explorers with a permit. The cave system is located beneath the Green River Valley of south central Kentucky. It’s easy to get lost inside the labyrinth, so stick close to the group!

Spook Cave, Iowa

The town of McGregor, Iowa, hides something a little spooky underneath its soil. Spook Cave, a flooded system that can only be accessed by boat, is a unique cave system that offers an otherworldly experience. Though locals will try and tell you it’s haunted, we’ve never seen any ghosts floating beneath the watery tunnels. Yet. The downside to Spook Cave is that it’s privately owned, so obtaining a permit to explore can be downright impossible. The commercial tours of the cave are still a fun time, and a great option for explorers with children in tow.

Meramec Caverns, Missouri

Binkley Cave System, Indiana

The Binkley Cave System in Indiana only opened up to the public in 2013 and is quickly amassing a large following. Inside, the caverns boast incredible waterfalls, Ice Age dinosaur bones, water-filled tunnels and even some gems to mine. As a newly discovered cave, you can bet there are still plenty of passages that have yet to be explored. Permits are handed out sparingly, and only to experienced spelunkers. Even if you’d rather check out Binkley on a guided tour, it’s still one of the best underground spectacles in the state.

Foglepole Cave, Illinois

Foglepole Cave is one of the least disturbed caves left in Illinois and the Midwest, making it prime real estate for adventure. Luckily, permission is still regularly granted to explore for seasoned spelunkers. The large cave system is spread across 27 acres in Monroe County and features miles of passages still waiting to be discovered. Since it’s vastly untouched, not a lot is known about the conditions inside the cave. However, the region does host a large array of species, including bats, in a setting somewhat similar to the Ozarks. Go in, but leave as much undisturbed as you can.