Gleaming self-built castle towers made from beer cans and inspired by "Vitamin Mary Jane."

At the tallest peak in Colorado, an electrifying mix of thin air, lightning, and rivalry.

Where scientists keep miles of very valuable ice from Antarctica and Greenland from melting.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

Rather than a run-of-the-mill franchise hotel, this lodging has been decked out in dinosaur decor.

This spectacular track has run continuously since 1882.

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

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

When ecosystems collide in the arid Southwest.

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

This modern antique shop is a museum for 1980's Saturday morning cartoon culture.

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

The childhood home of Henry Jones Jr. is now an adventure-themed bed and breakfast.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

A 300-ship graveyard, with a few still visible at low tide.

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A psychedelic labyrinth on the San Francisco bay.

The first presidential bomb shelter was located in an old vault under the Treasury, connected to the White House via tunnel.

One of the largest artillery pieces in the world sits in a Washington D.C. parking lot.

Home to a vast and influential collection of Shakespeareana.

There's a crumbling old mansion inside the Smithsonian National Zoo.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.