High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

Collection of vintage trailers double as hotel rooms.

One of the largest, oldest, darkest, quietest motel rooms in the world.

Eons ago, a rushing lava river formed this pristine passage through solid rock.

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

This mesmerizing medieval monastery-cave complex sits thousands of feet above ground overlooking a valley.

Monty Python fans will recognize this abandoned mine as the Cave of the Killer Rabbit of Caerbannog.

More gold than anywhere else, ever.

An architect's childhood fantasy treehouse made real.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

This 29-ton granite ball spins around at the slightest touch thanks to a scientific phenomenon.

One of the world's largest telescopes, stares into the night sky with two huge mirrors.

A stone pillar commemorates the surrender of the extraordinary Apache leader.

Hike the unusual hoodoos and rock formations that form this little-known natural wonder.

This fireplace-turned-monument pays tribute to the assassinated U.S. president.

The remote resting place of a notorious Wild West outlaw whose death is shrouded in mystery.

A once-booming Mississippi River town with a history of racial violence is now eerie and mostly abandoned.

A small side chapel in Santa Fe's basilica is home to the oldest statute of the Virgin Mary in North America.

The remote outlaw hideout of Jesse James, Butch Cassidy, and the Sundance Kid.

The notorious Wild West outlaw was raised in this unassuming abode.

The show's fictional Korean medical camp was created in the Santa Monica hills.

High on a hill overlooking Los Angeles lives a world famous, high power conical Tesla Coil.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.