The fifth-longest natural arch in the world, and the longest outside China.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

These aggressively sustainable art homes look like something out of 1970's science fiction.

A multi-storied adobe complex has been inhabited for more than a thousand years.

A unique blue and yellow phone booth in America's "Little Sweden."

A diverse, expansive nature preserve in northeastern Kansas.

The Bucyrus-Erie model 1850B electric shovel, or "Big Brutus," the largest existing electric shovel in the world.

A 20-foot-tall egg painted in a traditional Czech patterns by the Czech community in Wilson, Kansas.

A hotel with a rich Wild West history of miners and bootleggers.

One man's love for East Coast diner culture brought an entire eatery all the way from New Jersey to Colorado.

This was once the home of Gahan's Saloon, Denver's most storied speakeasy.

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

Explore some of the most unique vehicles in history along with a cast of unsettling mannequins.

Small teepee-like houses built for TB patients have become sheds, studios, and bus stops around Colorado Springs.

This iconic science fiction house still looks like something from the future.

The final resting place of American icon Buffalo Bill, and a museum that aids in telling his tale.

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

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

This spectacular track has run continuously since 1882.

Abandoned silver mine strewn with wrecked and twisted structures.

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

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

Once a mortuary that held the remains of Buffalo Bill, this Denver hotspot is now a death-fixated restaurant.