The mysterious canine hides atop a drain pipe on the back of the building, some say as a sneaky shoutout to Yale.

Nassau Hall has served as army barracks, a museum, and played a key role in the American Revolution.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

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

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

A replica of the famous memorial statue at the Normandy American Cemetery hides in an office building in downtown D.C.

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

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

A centuries-old church stands as a testament to Boston's "father of architecture."

Narrowest house in Boston.

Historic Hull Street was actually the first street with a proper name in the Boston area.

The statue of John Harvard isn't actually John Harvard—or even, technically, the founder of the school.

A miniature train theme park, free to the public, laying at the base of the Santa Monica Mountains.

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

One of the largest collections of wildlife art in the United States, built into the side of a cliff in rural Wyoming.

Thirteen pastel palaces in downtown Charleston add a gorgeous splash of color to the city.

South Carolina's last remaining slavery auction house is now a museum devoted to its own tragic history.

One of the oldest living oak trees in the Southeast.

This tribute to the 16th-century composer is now an unusual shrine to Michael Jackson.

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

Paris' linguistic guide to the international language of, yes, love.

This surreal statue brings a famous French novel about a supernatural cad to arresting life.