The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

A superbly preserved example of Georgian residential architecture that was once home to one of the founders of Alexandria, Virginia.

The final resting place of an unidentified revolutionary soldier sits behind a Virginia church.

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

This grave marks the passing of a historic Jane Doe whose identity remains a mystery to this day.

An enormous, inside-out glass globe built in 1935.

Washington D.C.'s most famous pianist, composer, and bandleader still tickles the ivories outside Howard Theater.

It was once the base for a series of domestic terror attacks.

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

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

There’s a hidden military meme engraved on the World War II Memorial.

Decades before the scandal, this staircase on the river was a literal "water gate."

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

For 60 years, the academy had no permanent location until members voted Washington D.C. as its forever home.

The word "Watergate" will forever be associated with the infamous scandal in 1972, but this fountain is famous in its own right.

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.

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

Outside the Department of Transportation, a collection of artifacts honors the history of how we get around.

A fantastic array of trays and cables once whisked books over to the Capitol at 600 feet per minute.

A promising candidate for the lost rock laid by George Washington was unearthed, but the hunt is still on.