A little-known subterranean street runs under some of the best-known buildings in Chicago's River North.

This landmark of the Chicago silent film industry may not be in the picture business anymore but it still stands proudly.

Chicago's largest cemetery is full of beautiful Victorian monuments and more than a few ghost stories.

More than 8,000 drinking jugs say “Cheers!” to a guy named Toby.

Illegal drag racing two stories beneath Chicago’s streets.

This award-winning men's bathroom was just too beautiful to not allow women to see.

This limestone outcropping was once a ceremonial site for ancient Native Americans.

The small cave that housed Tennessee's "first citizen."

This winding road of 318 curves is a must-visit for (careful) motorcycle and sports car enthusiasts.

A historic dam made famous for its turbines and feature in a Hollywood classic.

Enormous lake at the bottom of a unique cave system.

The perfectly named cave drop is the deepest in the continental United States, almost matching the height of Seattle’s Space Needle.

An abandoned theme park with a strange and tumultuous past.

Amazing taxidermy dioramas from the 1960s in a cement building meant to look like an ice cave.

Hiding behind a grocery store is a spectacular cavern carved as part of an old limestone quarry.

This stone incorrectly marks the 35th parallel, causing some territorial kerfuffles.

This large cave is a summer home to thousands of bats and has a rich history dating back to prehistoric times.

This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.

The remains of this visionary community can still be found much as it was a century ago.

Crumbling Kennedys and a decaying Tecumseh are just some of the haunting remains of one man's cement art trail.

Veritable museum of 20th century country music history.

This simple, broken column marks the final resting place of one of America's most famous explorers.

Home of an evil witch famous within southern folklore.

This mansion turned restaurant was once a pitstop for Al Capone during his travels.