During Prohibition, the U.S. Congress had an "official" bootlegger, with his own Capitol Hill office.

The school tested mustard gas for the U.S. Army during World War I.

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

"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!”

More than 500 unique and specially designed cases collected by D.C.'s "Harmonica Case Man."

These abandoned waterworks are crumbling into the Potomac River.

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

The early data processor factory founded in Washington for the 1890 U.S. Census went on to become IBM.

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

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

A small token of gratitude from freezing cold journalists who were given a warm haven while covering JFK's inauguration.

Before Metro, Washington had a robust streetcar network—and you see the remains of this infrastructure if you know where to look.

Behind an abandoned storefront is an example of pioneering 1930s gas station architecture.

The 28,000-year-old specimen is remarkably intact.

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

Atop this media building, two hives containing more than 30,000 bees keep the surrounding area vibrant.

Press 1 for knock-knock jokes.

Helen Keller once broke ground on this historic center for the study of technologies to benefit the hearing impaired.

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

A surprising, but overlooked example of geology in the middle of the nation’s capital.

The fountains of the U.S. Navy Memorial are annually salted with water from the Seven Seas as part of a nautical ritual.

There just so happens to be a court even higher than the U.S Supreme Court: a basketball court in the building itself.

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

Also known as the Founding Church of Scientology.