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

Mysterious 500-year-old tapestries depict a unicorn hunt.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

One of only two commuter aerial tramways in the United States.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Elevated freight railway turned wildly successful urban park.

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.

The U.S. Navy’s preposterously detailed mini battleship took 77,000 hours to complete.

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

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

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

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

An easily overlooked memorial to a Ukrainian famine-genocide that killed over 4 million people.

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

Go take a picture with the inventor of the daguerreotype photographic process.

A much-maligned monument to teetotalism.

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

The Kirkland Monument remembers a selfless Civil War hero who braved the battlefield to give water to his dying enemies.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

There’s a hidden military meme engraved on the World War II Memorial.

The house where John Wilkes Booth conspired with his co-conspirators.