A Norwegian-born sculptor created these soaring guardian angels at the entrance to Hoover Dam.

This picturesque cliffside beacon no longer calls to sailors but shines once a year in honor of a famous shipwreck.

Minnesota's oldest and deepest mine is now an underground physics laboratory.

At this Minnesota state park you can easily wade across the source of the mighty Mississippi.

The only rotating bar in New Orleans has been slowly spinning since 1949.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

The only visible piece of San Francisco's most famous shipwreck.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

Look closely and you’ll notice that the color changes a third of the way up the tower.

There’s a hidden military meme engraved on the World War II Memorial.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

Illegal drag racing two stories beneath Chicago’s streets.

This $3 million model train takes you through Chicago, Seattle, and the thousands of miles in between.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

This historic hotel invented the chocolate brownie.

These pretty kitties killed and ate as many as 135 railway workers.

This southwest-styled home in Santa Fe claims to be the oldest house in America thanks to an ancient bit of foundation.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

This museum started as a collection of Manhattan Projects and continues to add exhibits as they are declassified.

Officially named the "Loneliest Road in America," this barren stretch of Nevada road offers almost nothing but sky and open fields.

A gothic palace of endless stalagmites and pseudoscorpions waits within one of the world's most beautiful caves.

A 90-foot-tall psychedelic "tree" on the side of the highway has baffled passersby for decades.