Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

Housing the National Women's Party since 1929, this historic house is now a monument to the fight for gender equality.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

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

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

A wondrous old library overlooking the nation's capital.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

This grand gothic brewery has been pumping out suds for over a hundred years.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

The United States Capitol's former columns still stand.

Before Nixon, "watergate" meant canals.

A derelict bit of transportation infrastructure hidden in the woods.

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

A super-sized promotional trick that is now a D.C. landmark.

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

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

This forgotten boat elevator was an engineering marvel in its heyday.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

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

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

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