While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

Before Nixon, "watergate" meant canals.

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

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

Perhaps the most scandalous statue of America's first president.

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

The most accurate timepiece in the world.

The "lovely red Vega" of the legendary record-settling pilot.

The oldest continuously operating fish market in the United States.

The national park was once a plantation estate.

Government testing at the asylum briefly explored using marijuana as a "truth serum" on Nazi prisoners of war.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

A collection of comics, graphic novels, animation and caricatures devoted to exploring this often overlooked art form.

Catacombs turned marketplace.

England's most famous front door has an accidental doppelganger.

The next-door homes of two very different musicians, George Frideric Handel and Jimi Hendrix.

Residential building on the Regents Canal is a breeding ground for creativity and innovation.

Bronze sculpture celebrating the relationship between Churchill and Roosevelt.

This overlooked street light once served as a KGB dead letter box.

This London marker celebrates the spot where the world-famous English band was founded.

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

A living memorial to the trees London lost during the Great Storm of 1987.

The medieval woodcut-style artwork chronicles life in medieval London.