This mosaic-covered bar is brimming with curated curios.

This majestic tree has survived 400 years of storms, droughts, and floods, and is a beloved natural landmark in Missouri.

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.

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

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

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

Tucked away between two 19th-century buildings, this small shop specializes in the macabre.

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.

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

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

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.

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.

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

This sprawling farm was once a Cold War-era hideaway for the nation's top diplomats.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

The U.S. Army's giant warehouse of war art includes Hitler’s watercolors and Norman Rockwell oil paintings.

The only place for a truly presidential dram.

America's first federal monument.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

This war hero's old shop remembers the fine line between medicine and quackery during the Revolutionary War.