A Yale University president wears full samurai garb in one of America’s oldest cemeteries.

Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

An elaborate memorial to a man local legend says died of a broken heart.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

Little Red Lighthouse under the George Washington Bridge.

A winding district gerrymandered into the shape of a mantis.

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 privately owned cemetery that holds room for Washington's finest when they step down from life.

Daredevil repair workers can worm their way out the access hatch, loop ropes over the apex and rappel down the monument.

The grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

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

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

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

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

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

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

Two dozen pinball games hidden away inside a most unlikely location.

The first piece of public art dedicated to LGBT rights.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

Walking around West Harlem reveals a scavenger hunt of beautiful bird murals.

A deteriorating 1990s Girl Scout camp in a beautiful lush park on Lake Ontario.

The remains of a failed subway in upstate New York is now an underground graffiti bunker.

Rochester's signature culinary delicacy.