One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

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

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

Before founding the American Red Cross, Clara Barton had a tremendous humanitarian impact by locating thousands of missing soldiers.

Every drop of D.C. tap water flows through this old waterworks.

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

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.

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

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

Senators used to relax in the nearly forgotten marble tubs now hidden in the U.S. Capitol Building's basement.

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

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

Daredevil repair workers can worm their way out the access hatch, loop ropes over the apex and rappel down the monument.

This robust fence in front of a historic Georgetown home is likely made from hundreds of recycled Revolutionary War firearms.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

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

A diminutive plaque recalls the treetop sniper who almost killed Abe Lincoln.

A diminutive memorial marks the site of a successful assassination by a right-wing death squad in America's capital.

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

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

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

Obscure Freemasons still live in D.C.’s largest private residence.

One of the largest artillery pieces in the world sits in a Washington D.C. parking lot.