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

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

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

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

The scant remains of an expansive indigenous civilization can be seen at this Arkansas state park.

This historic hotel on Bathhouse Row in Hot Springs National Park has a storied history of gangsters and baseball greats.

The house where the famed outlaw was shot by a dirty coward is now a museum to the criminal's legacy.

Two hundred tons of pioneer artifacts were painstakingly recovered from a shipwreck at the bottom of the Missouri River.

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

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.

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

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

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

On the side of Arkansas' Great River Road stand the remains of a forgotten World War II POW Camp.

The Old Mill shown in the opening credits of “Gone With the Wind” is actually fairly new, and was never a mill at all.

The legend of a local monster still haunts this small town.

The only diamond mine in the world where you can keep what you find.

In rural Iowa, an imported 19th-century windmill overlooks an unlikely enclave of Danish culture.

A warning to the weak-kneed: This narrow bridge does its swinging eight stories high.

While there are no actual snakes in the history of this crooked road, there may be a number of dead horses.

A floating museum that was sunk by a flood and left to rot in the tides.

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

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

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