There's a unique hiking and biking trail in Illinois that has witnessed a lot of history. It dates back to 1829 and is a whopping 45 miles long. The beginning and end points are Harrisburg and Karnak, Illinois. Be advised that it's not a smooth, flat 45-mile pathway. There are inclines, and gravel paths; it's challenging, according to Enjoy Illinois.

Illinois Department of Natural Resources
Illinois Department of Natural Resources
loading...

There are a lot of interesting sights and scenery along the way.

The trail used to be a railway back in the 1920s. Considering how long the trail has been in existence, it's not surprising the path leads through ghost towns as well as seven existing towns. The trail runs for 45 miles from downtown Harrisburg to Karnak in southern Illinois. Explorers will encounter ravines, rocky streams, and lots of farming fields. You'll also see marshes, streams, ponds, and bottomland woods.

Is it the longest trail in Illinois?

Not even close. (Cue: The Proclaimers "I'm Gonna Be (500 Milles)") That honor goes to The Grand Illinois Trail. It's an astounding 500+ miles long. But, it doesn't have a cool tunnel like this.

Tunnel Hill Trail has a 500-foot-long tunnel that was part of a late-1800s railway used to transport coal and other items.

Illinois Department of Natural Resources
Illinois Department of Natural Resources
loading...

Don't be fooled by the light at the end of this tunnel because it will take quite a while to reach it from one end to the other. Most of the tunnel is complete darkness. In fact, Only In Your State recommends bringing a long flashlight or using the light on your phone when walking through it.

10 Illinois Ghost Tours That Guarantee To Scare Your Pants Off

The 25 Smallest Towns in Illinois

These towns are so small, if you blink, you'll miss them.

More From WGBFAM