The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.

Abandoned businesses, homes, and rusted cars are all that remains of this stopover town.

Despite being one of the most photographed vistas in the Rockies these twin peaks are rightfully known as the "Deadly Bells."

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

The spot in the Mile-High City that's exactly 5,280 feet above sea level (at least for now).

The superstar of Cold War nuclear bunkers has been featured in countless films but is now barely operational.

Hidden beyond a kitschy giant beetle is this remarkably sprawling collection of preserved insects.

The ghostly remains of an accidental sea.

A museum dedicated to a sea that should have never been.

Thanks to a quirk of elevation this gift shop produces magic doughnuts that are found nowhere else on Earth.

The remains of a World War II munitions factory still haunt the fields of this Twin Cities suburb.

The scene of one of the darkest moments in American labor history has been left essentially untouched since the tragedy.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

The top of a giant mesa, just outside of Amarillo, appears to float in the sky above.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

One of the greatest heroes of the Titanic tragedy came from humble beginnings to this beautiful home.

The largest self-built castle in the U.S., six decades in the making.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

The highest bridge in America was built for an almost unnervingly small amount of money.

This grand stone tower was dedicated to a famed American humorist almost by coincidence.

The haunted reputation of these abandoned Colorado train tunnels is probably not helped by the terrifying spiked fence.

The moving metal works of one troubled artist can still be viewed on his front lawn... for now.

This Boeing KC-97 tanker is now a restaurant for aviation lovers.