A popular swimming hole that hides one of America's most deadly diving spots.

This unique structure in suburban Austin is made up entirely of other people's castaways, and constantly changing.

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

A small pack of an ancient, hairless breed of dog once believed to guide souls through the underworld lives on its grounds.

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

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.

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

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

This naturally-sourced hot spring is now home to a clothing-optional resort.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

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

A technicolor place of worship for Elevationists.

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."

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

This oddity shop contains everything from antique tools to a human skeleton.

New Plymouth, Idaho is the only U-shaped town in the United States.

This trail leads to a mine that was used as a sanctuary during the Great Fire of 1910.

Tucked away on a scenic trail, a modest memorial honors one of the greatest writers of our time.

Three generations of intrepid collectors display their curious artifacts in a homemade museum right next to the caves they discovered.

Supposedly Satanic numbers adorn this preserved submarine sail.

These century-old beehive-shaped kilns were built to produce charcoal for nearby mines.

An Idaho legend carved out a cave village with his own two hands.