The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

This award-winning men's bathroom was just too beautiful to not allow women to see.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

Enormous lake at the bottom of a unique cave system.

This funicular railway rumbles along for a mile up the nearly vertical face of Chattanooga’s Lookout Mountain.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

Like Mardi Gras, only everyone's a pirate.

Nevada's largest cactus collection stands outside a candy mogul's small factory.

One of the world's tallest Ferris wheels takes visitors high above Las Vegas in a spinning party room.

The grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

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

An overlooked memorial honoring the local Washington residents who died in World War I.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

Decades before the scandal, this staircase on the river was a literal "water gate."

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

This surprising gem is a world-class archeological museum hidden at the University of Chicago.

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

Nonprofit art center that promotes outsider, intuitive, and self-taught art.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

There are lots of hands and feet stamped in the cement in front of Grauman’s Chinese Theater, but Mel left behind something extra.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

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.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.