This historic cliffside mansion uses a natural cave for air conditioning.

Speak to a companion on the other side of the room loud and clear through this architectural anomaly.

An unexpected but incredible collection of wildlife dioramas spanning rainforests, swamps, forests, and plains.

A kitschy, creepy St. Louis mainstay.

A remarkably opulent mansion with a tragic history.

The red brick house where the father of rock 'n' roll wrote some of his classic hits.

A subterranean haunt where wine and homemade biscottis are always on the menu.

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

What was once a presidential estate is now an exotic menagerie and home to the Budweiser Clydesdales.

The world's largest collection of fine-scale miniatures and one the nation's largest collections of antique toys.

A historic house in St. Louis was plagued by a series of suicides committed by family members involved in a successful brewery.

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

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

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

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

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

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

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

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

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.

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

Less a museum than a bizarre fantasy world created by artists and engineers.

An artistically engineered dam designed to honor the relationship between humankind and nature.

In one man's basement, the world's largest collection of Kansas City Chiefs memorabilia is on display.