The iconic D.C. restaurant where the Cuban Missile Crisis was negotiated, now a Walgreens.

Through the decades, Black music stars have performed at this historic hub for music and the arts.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

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 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 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

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

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.

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

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

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

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

A historic arena where the Beatles played their first concert in the U.S.

Art deco landmark on the outskirts of Washington, D.C.

Go take a picture with the inventor of the daguerreotype photographic process.

A small triangle of DC grass is the final resting place of one of Sonny and Cher's songs.

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.

You could be standing at the site of one of D.C.'s most fatal tragedies and not even know it.

Largest Roman Catholic church in North America.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

Home to items never before seen by the public.

This centerpiece of the Hollywood & Highland shopping center is a recreation of a long-lost movie set.