The only completed wing of Utah's first capitol is filled with artifacts and odd stories about its past.

Where a guard killed nine German prisoners during one of the worst 20th-century POW camp massacres in U.S. history.

A new kind of theme park for adults off the Las Vegas Strip.

The rocks in this arid basin leave trails of movement behind them.

A massive hydrovolcanic explosion left a half-mile wide crater in Death Valley.

An abandoned Jazz Age dream home and con man's hideout in Death Valley.

This magnificent, quirky home sits atop a literal gold mine in the middle of the Nevada desert.

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.