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.

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!”

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

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

Washington's iconic carousel has a nice piece of Civil Rights history.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

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.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

It was once the base for a series of domestic terror attacks.

Home to items never before seen by the public.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

Trick water gardens from 1619 featuring a 200 piece mechanical theater powered by water.

The beautiful, ornate weather station is the most popular geocache in Salzburg.

On a winding Vienna side street, one museum has turned their windows into a monument to history’s peace-minded heroes.

Legends surround an ancient tree trunk riddled with nails for good luck.

Baroque celebration of the end of the Great Plague of Vienna.

Golden cobblestones remember a time when this small alley was used to avoid having to give a Nazi salute.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

The patron saint of spinsters grasps a container of dried blood.

Daily jousts and dancing barrel makers in Munich's mechanical clock.