Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

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

A place where the laws of nature seem to have gone completely berserk... but of course haven't.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

There are eight natural springs around town, each with a slightly different taste.

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

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

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

When ecosystems collide in the arid Southwest.

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

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

An enthusiastically interactive mining museum that won't let black lung ruin the fun.

At one time this small mining village was the highest town in America but now it sits abandoned while the mine churns on.

Abandoned silver mine strewn with wrecked and twisted structures.

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

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

The summer home and later final residence of acclaimed American sculptor Augustus Saint-Gaudens.

Come for the gun-toting hillbilly madman, stay for the ice-cream loving basketball bears.

Known as one of the most climbed mountains in the world, this barren peak is permanently bald thanks to an anti-wolf fire.

Beautiful natural falls where Satan once ruined a pot of beans.

A classic roadside attraction on Vermont's historic Route 5.

Tour the world's largest deep-hole dimension granite quarry, where you can view the plant where gravestones are made and roll a ball down the outdoor granite bowling alley.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.