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

A giant concrete orb in far north Iceland marks the ever-shifting boundary.

A research lab and hands-on museum where visitors can experiment with retro technology.

The largest brick bridge in the world.

The quiet canyon has a tumultuous history involving a doomsday cult.

If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

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

Antique automobiles, phonographs, organs, and farm equipment.

This razorback ridgeline has doubled as a scenic drive since the early 1900s.

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

Once an unstoppable source of gold and silver, this town came to a grinding stop when the groundwater proved deadly.

The remains of the dam that unleashed a 15-foot wall of water on Denver.

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

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

The moving metal works of one troubled artist can still be viewed on his front lawn... for now.

One of the largest Buddhist stupas in North America is built of concrete designed to last 1,000 years.

Even in death, he's still your huckleberry.

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

The largest source of fossilized insects anywhere.

Abandoned silver mine strewn with wrecked and twisted structures.

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

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

This "zoo" is a cross between a junkyard and a sculpture garden, featuring animals you won't see anywhere else.

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