The rogue roots are gradually consuming some of the historic marble grave markers.

This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.

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

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

The most decorated dog of World War I is preserved in the Smithsonian.

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

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

This unique historical monument features large concrete spheres designed to resemble fallen stars.

This church built atop a gas station promises to "equip you for the next stage in your life’s journey."

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

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

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

"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!”

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

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

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

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

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. Fish Commission’s effort to mass produce carp.

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

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

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

Two thirds of this Montreal neon icon has survived to flash another day.

The biggest museum dedicated to insects in North America, one of the largest in the world.