A mammoth pair of Civil War artillery guns abandoned out in the forest.

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

America's first federal monument.

This simple stone memorial remembers a secret, Geneva Convention-defying interrogation base from WWII.

Hidden in the forest atop a long, winding driveway is this stately home.

Before Nixon, "watergate" meant canals.

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

The house where John Wilkes Booth conspired with his co-conspirators.

A benevolent, 16-foot-tall river dragon lives on a suburban lawn.

A historic cemetery with unique artwork, a Civil War fort, and also happens to be the site of the Battle of Bladensburg.

The 72-foot giant escaped confinement in a large patch of mulch only to be reburied in the sandy shores of the Potomac River.

An unusual sculpture, an interesting history, in a strange place, for a good cause.

A historic cemetery filled with quirky faux wood art and unique tombstones.

The rooster who crossed the road lives on forever in Takoma Park, Maryland.

This ruined quarry once produced the distinctive red sandstone used for construction projects in Washington, D.C.

The whole world in one water tank.

The final resting place of the tragic king and queen of the Jazz Age is tucked away in a small Maryland graveyard.

The ruins of this long-abandoned unsuccessful gold mine can still be found.

A graveyard that dates back over 200 years stands near a busy shopping center.

This brick-lined pedestrian walkway was once a railway tunnel used during the Civil War.

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

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

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

This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.