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

Corn-inthian columns with a uniquely American take on neoclassical architecture.

The first memorial dedicated solely to the Black troops who fought for the Union.

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

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.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

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

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

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

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

A much-maligned monument to teetotalism.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

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

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

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

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

A museum cafe showcases Native American dishes and indigenous ingredients from across the Western Hemisphere.

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

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

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

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

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

Housing the National Women's Party since 1929, this historic house is now a monument to the fight for gender equality.