Illinois' Coolest Underground Destination Is This Stunning Geological Wonder Full Of Unique Wildlife

Since 1901, travelers have been making their way to a secluded spot in Monroe County, Illinois, about 45 minutes south of St. Louis, Missouri. Their goal isn't to go boating on the nearby majestic waterway known as "America's River" — the Mississippi — it's to descend to a fascinating location deep below the ground. Illinois Caverns is located on what was once a small farm and is today a protected State Natural Area. Though there are many other caves you can visit in the U.S. (you can even take a cave road trip across the border in Missouri), Illinois Caverns is one of the coolest caving destinations you could hope for. 

For one, this is a 6-mile-long section of a wild cave system. Some caverns are altered to make them more appealing to visitors, which can mean anything from hanging a few colorful lights to adding a tram pulled by a Jeep to create ride-thru cave tours. However, when you enter Illinois Caverns, you are primarily seeing what formed naturally rather than human-made additions. There aren't even any lights, so the only illumination is the light you bring with you. 

Second, you won't have anyone to guide you on this adventure. Other popular caves, like Kentucky's impressive Mammoth Cave for example, offer interesting cave tours led by park rangers and experts who can point out interesting rock formations and teach you about the history of the cave. In contrast, you and your hiking buddies will have to enter Illinois Caverns totally on your own. For those brave enough to take the journey, many wonders await in this unique underground world.

A journey into Illinois Caverns allows you to step into a place unlike any you've known before. And it's teeming with life, including plants, fungus, insects, worms, two species of bats, salamanders, and tiny creatures known as Illinois cave amphipods that thrive in the cave's underground stream. To visit, however, you'll need to plan ahead. The cave is only open to visitors from 8:30 a.m. to 3:30 p.m. Thursday to Saturday between the months of April and October. While the cave is completely free to visit and you won't need to schedule a tour, you will need to fill out a permit application and recruit a few other adventurous souls to go with you. While the idea of being completely alone with the cave creatures might seem exciting to some (albeit horrifying to others), only groups of at least four people are able to enter this mysterious world. 

The Illinois Department of Natural Resources requires everyone to bring at least three battery-powered flashlights or lanterns and a hard hat or helmet for safety. While it's not mandatory, you should also plan to bring water, as you cannot drink any water from the cave for health reasons. Wear hiking boots or sturdy shoes with good traction so you won't slip when climbing up and down ladders and walking on the slimy cave rock. There is a perennial stream and waterfall in the cave, and in places the water can be very deep. Even if you don't wade in the stream, the cave is generally damp, so anything that can be damaged by water probably will be if you don't put it in a waterproof bag. This is an especially important consideration when it comes to your phone and the batteries for your light sources.