This 17th-century street hidden beneath Edinburgh was once a breeding ground for the black death.

The world's widest single drop waterfall, and the two men who legend says went over its edge in a boat.

Come for the speed, leave in love with the desert.

This tea house was a hand-built gift from Boulder's sister city in Tajikstan.

Wisconsin's most celebrated export gets the royal treatment on I-94.

A place to eat for on-the-run agents and espionage enthusiasts.

A mythical bird etched into the face of a rock doubles as the mascot for a nearby school.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

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

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

This is not your typical jungle gym.

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

The Magic House provides a beautiful and creative environment for curious youngsters to get their knowledge on.

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

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

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