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

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

This nine-story building is the oldest standing skyscraper in D.C.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

Disks are rolled out onto the south lawn to absorb the impact of Marine One's wheels like giant coffee coasters.

The innocent intentions of this monument are somewhat lost in the sculpture's muscled imagery.

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

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

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.

The oldest continuously operating fish market in the United States.

This eye-catching sculpture of rural life seems a bit out of place at a suburban intersection in front of a car dealership.

This local mascot has been a presence in the area since the 1960s.

Long buried under the 20th-century landscape, this lift lock of the Alexandria Canal is the lone remnant of an ambitious early American transportation project.

The narrowest house in America is seven feet of pure spite.

This small pedestal marks the spot of the first lot of land sold in Alexandria, Virginia in 1749.

A former major munitions plant that has been converted into a sprawling art space.

An original apothecary from 1792.

A massive, majestic mammal watches over pedestrians from his perch atop a former B.P.O.E. lodge.

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

This cannon dating to 1755 has stood guard at this suburban intersection since 1915.

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

The final resting place of two (or three) presidents, one vampire, and 18,000 Confederate soldiers.