2300-year-old Roman road connecting the empire.

The yawning maw of this pagan visage is said to bite off the hands of liars.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

Architectureal fantasy quarter of Rome.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

Xul Solar was an artist of alternate worlds, inventor of languages, and dreamer of utopias.

A series of waterfalls so massive they straddle the border of Argentina and Brazil.

This stunning mass of ice spans 121 square miles and is still growing.

This historic, palatial theater is now one of the world’s most beautiful bookstores.

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

Undone by Prohibition, this abandoned brewery-turned-flour mill is now ready for its third act.

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

This former small town was destroyed not by the motor oil it sprayed the ground with but by the toxic waste that was added.

A piece of John the Baptist in the American heartland.

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

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

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

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.

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

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

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.

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

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