Giant granite rocks standing end-to-end like a train of circus elephants.

If there's another drive-through golf-cart bar in a bat-filled cave on top of a mountain, we don't know about it.

A geological oddity formed by two rivers carving out a mass of limestone on both sides.

The show pony of cave systems, Fantastic Caverns manages to live up to its name.

A creepy sculpture of a decapitated head invites viewers to see St. Louis through its empty eyes.

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

Erosion and time have created a naturally-formed water park.

The "World's Largest Underground Business Complex," a 55,000,000-square-foot city underneath Missouri.

Curious cave that stays a cool 56 degrees all year long.

European castle ruins in an American state park are actually the product of death and grief.

Originally dubbed "Retirement" by the Navy Commodore who built it in 1780, this beautiful mansion is now the centerpiece of a suburban community park.

Burial mounds of prehistoric Native Americans who lived along the DuPage River.

The world's largest man-made underground caverns offer unparalleled underwater wonders.