An abandoned concrete jungle surrounded by a lush park.

Like Stonehenge, but with boats and oodles more charm.

A 35-foot-tall fork stuck in the ground outside an office building in Missouri.

The maximum security facility was once thought to have "the bloodiest 47 acres in America."

In the St. Francois Mountains in the Ozarks at 1,772 feet above sea level, Taum Sauk Mountain is the highest (and possibly oldest) peak in Missouri.

This is not your typical jungle gym.

This mosaic-covered bar is brimming with curated curios.

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

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.

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 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 man-made underground caverns offer unparalleled underwater wonders.

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.

The history of the treatment of mental illness, illustrated in all its gory detail, and housed in an asylum.

This abandoned prison castle has become an imposing gallery of graffiti art.

Once an ambitious nature spa, these forest ruins now provide a serene monument to failure.

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

An enormous goose sits atop this nest-shaped home.

This boulder stays on its mountain thanks to a huge chain and on the map due to local legend.

You can climb to the summit of Black Mountain, as long as you sign the waiver.