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

The national park was once a plantation estate.

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

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

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

They sort through millions of dollars worth of diplomatic gifts on behalf of the government.

Where the U.S. government kept its actual treasure, before Fort Knox.

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

A line of blue paint marks the route of the inaugural parade.

There's an old indoor swimming pool hidden directly underneath the White House Press Briefing Room.

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

A portal into the bricked up canal that runs through the heart of Washington D.C.

The site of the climactic scene from the classic horror film is now a historic landmark.

Before Nixon, "watergate" meant canals.

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

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

There’s a special club house at the top for the bell ringers.

When it comes to handsignals (and colonialism) rock always beats scissors.

A clone of a cloned tree that was so important it allegedly had its own guards.