The first presidential bomb shelter was located in an old vault under the Treasury, connected to the White House via tunnel.

Before Nixon, "watergate" meant canals.

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

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

This poor little statue is the most vandalized memorial in Washington.

The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

An obscure public service from the U.S. government that redeems burnt, moldy, and soiled old greenbacks.

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

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

D.C. once had its own tiny rival to the New York Stock Exchange.

The tunnel under the Capitol Building where Congress takes out its trash.

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

The only tennis court that falls under the jurisdiction of the central bank.

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

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

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

An easily overlooked memorial to a Ukrainian famine-genocide that killed over 4 million people.

Literal "money laundering."

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

An overlooked oasis of quiet on the grounds of Washington's monumental basilica.

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

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

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

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