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

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

This super steep hike ascends 2,000 feet in less than a mile.

These faux-cliff dwellings allow visitors to climb around on a replica archaeological site.

This Colorado hiking trail provides a small gold mine of abandoned gold mines.

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

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

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

Hidden beneath a bridge, this waterfall is known for the large amounts of graffiti painted on its base.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

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

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

The highway's southernmost spot is a beloved local attraction.

An idyllic swimming pool tells the tale of Hemingway's trouble with women.

A monument celebrating the idea of reaching inaccessible places.

In Florida, these naughty monkeys live on their own mini-monkey Alcatraz.

Welcome to old Florida, where a 1940s mermaid show is still enchanting visitors.

Where manatees are the snowbird vacationers in these balmy Florida springs.

This tiny 19th-century tunnel was built so a man could move his cows from one field to another.

One-of-a-kind museum inside the first Boeing 747-400 ever made.

This stone is a marker of one millionaire's personal vendetta against gravity.

An eerily abandoned stone tower is all that remains of a demolished dam on Cape Fear River.

The oldest bridge in South Carolina may have been designed by the same man who created the Washington Monument.