Waterloo, Illinois is a charming town in Monroe County. What you may not know is that there are over 100 recorded caves in this county alone. That is more than any other county in the state. If you are looking for an unforgettable adventure in Illinois, this is the only commercial cave open to the public in the entire state. Grab your spelunking gear, and several good flashlights, and get ready to explore the best cave in Illinois.

Now called Illinois Caverns, this cave system has been known by many names over the years, including Mammoth Cave, Egyptian Cave, Burksville Cave, and Eckert Cave.

The first attempt to commercialize the cave was in 1901. It wasn't very successful at that time and closed down in 1907. Another resurgence occurred around 1947 when the land on which the cave was located was sold to William Hayden.

He and his nephew tried again, expecting tourists from all over the state and country to explore the caves. Again, it didn't bring the expected turnout. Eventually, the cave was sold to the state of Illinois in 1985.

As the second-largest cave in the state, Illinois Caverns is a network of six miles of tunnels and passageways, all of which maintain a constant temperature of 58 degrees year-round.

Not your typical "touristy" cave, it gives you a more primitive cave experience. That's not to say you have to be a master spelunker to enjoy the fascinating twists and turns this cave offers.

The main path through the cave is considered a fairly easy walk-through. However, there are a number of side channels that offer plenty of nooks and crannies to explore for those who want a more challenging caving experience.

It is a beautiful natural cave filled with stalactites, stalagmites, brimstone dams, flowstone, and soda straws. All were created as water flowed over the limestone and dolomite bedrock over millions of years.

Some of these enchanting formations look alien in nature, or like giant melting soft-serve ice cream cones, depending on how you look at them.

If spelunking seems a little more dangerous or more adventurous than you are used to, Illinois Caverns is the perfect cave to test the waters. There is only one way in and one way out, and the path is clearly marked.

If you simply follow the stream that runs through the cave, you will be okay. Safety equipment is required, of course, like a hard hat (even a bike helmet counts), a good pair of hiking or wading boots, and several flashlights per person. But overall, this is a great cave to explore for beginners and experts alike.

With so many unusual and exciting sights to see inside the cave, a day exploring Illinois Caverns is certainly an unforgettable adventure.

Best of all, the cave is now free to explore for parties of at least four people after filling out a simple cave permit. The caverns are open from April through October on Saturdays and Sundays from 9 am to 3 pm.

While there are many caves in the area, this is the only one of its kind open to the public. Would you agree this is the best cave in Illinois? Have you explored any amazing caves in Illinois or elsewhere? Tell us all about your adventures with a comment.

Be sure to try more one-of-a-kind adventures in Illinois and let us know what you think.