A public art jibe at one of the United States’ oldest and longest-serving senators.

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

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

An eccentric garden of sculptures crafted in India decorate an Irish green space dedicated to Alan Turing.

Part of a WWII submarine is lurking outside the Washington Navy Yard parking lot.

‘Bush the old fire dog died of poison July 5th, 1869. RIP.’

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

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

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

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

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

A clone of a cloned tree that was so important it allegedly had its own guards.

The hidden offices underneath Memorial Bridge have been locked up since 1976.

A brass plaque dedicated to a convicted cannibal hangs in the National Press Club, and that's not even the craziest part of the story.

These recently uncovered walls are all that's left of Washington, D.C's first defense contractor.

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

Military and first responders can test their skills in a Foggy Bottom mock station down in Georgia.

Literal "money laundering."

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

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

100 years later, they're still down there.

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

Where the U.S. government kept its actual treasure, before Fort Knox.

The famous abolitionist’s preserved estate is one of Washington's finest monuments to its great Black citizens.