A former mental hospital founded in the 1930s by a eugenicist who advocated for the forced sterilization of patients.

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

FDR's Art Deco hospital tower was hopelessly inefficient.

An astounding collection of medical specimens, including bits of President Lincoln.

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

She stares out across six lanes of traffic, clutching a musket and infant with determination.

An intricately designed junk art house with four extravagant junk art cars hidden in the suburbs.

Politicians, bureaucrats, and military officers gathered in this field near the Capitol to settle their disputes with blood.

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

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

Every drop of D.C. tap water flows through this old waterworks.

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

A Civil War fort in the middle of Washington, D.C. has been swallowed by a forest.

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

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

Please don’t anchor your boat onto the Department of Defense’s underwater data cables.

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

During Prohibition, the U.S. Congress had an "official" bootlegger, with his own Capitol Hill office.

There just so happens to be a court even higher than the U.S Supreme Court: a basketball court in the building itself.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

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

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

An ear-piercing buzzer calls lawmakers to a vote with a series of long and short rings to form coded messages.

The walls of the iconic dome are hollow and have a secret stairway.