This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

Baltimore's classic clock tower was once topped by a rotating, 20-ton medicine bottle.

The man who first patented the Ouija board rests in peace beneath a headstone that playfully reflects that achievement.

A blank headstone topped with a pile of pennies marks the final resting place of the infamous assassin.

This grisly headstone doesn’t seem to be resting in peace.

The tomb was guarded by soldiers from both sides of the war, and some left their initials carved in the brick.

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

An eerie, decaying ghost town destined to fade into the forest.

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.

Obscure Freemasons still live in D.C.’s largest private residence.

Was there a small "backpack nuke" hidden in the attic? JFK apparently thought so.

Affectionately known as "Lord Bot," this historic statue has a cult social media following and rightly claims to be “the most metal inhabitant of the Wren Yard.”

To avoid the demolition costs this abandoned drawbridge was simply left in the up position.

The system of air guns are fired off remotely to scare any trespassing avians.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

A tour de force of a fountain, memorializing a man who loved fountains more than anything else.

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

The Virginia home of one of the signers of the Declaration of Independence is being preserved with a unique glass facade.

The Virginia farm where John Wilkes Booth met his grisly end is now largely forgotten.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

Government testing at the asylum briefly explored using marijuana as a "truth serum" on Nazi prisoners of war.

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

A small triangle of DC grass is the final resting place of one of Sonny and Cher's songs.