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.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

This ancient monument has been dissembled and put back together at least twice.

The only example of a Paris Métro sign in use at a subway station outside of the French capital. 

A bronze statue commemorating his royal meowjesty, Toulouse.

This awkward aquarium sculpture is one of the strangest statues in Chicago.

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

The palatial McDonald's that inspired Wesley Willis.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

Only through the lens of a microscope can visitors see the true treasures inside this museum.

You can walk through the first Boeing Air Force One, which famously carried JFK's casket from Dallas back to D.C.

A shining memorial to a Belgian hero is said to bring luck to anyone who touches it.

A unique collection of Western and Japanese-style graves.

Take a stroll through the history of prams, carriages, and other ways we move babies around.

No one's quite sure where this quirky university tradition originated.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

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

Try not to get slimed in Tribeca.

Equal parts record-breaking temple to consumerism and bizarre fun park, it's more than you think it is...

These rows of World War II-era bunkers were the scene of some of the infamous Mothman sightings.

Roadside display for a popular fruit and vegetable stand.

A grand New York post office that is home to mailman Santas, scraps of postal history, and a pneumatic mail system.