Giant acorn-shaped 19th century gazebo from which suburban Washingtonians gazed upon the original "silver" spring.

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

Concerned residents saved this historic house and garden from demolition.

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

This rowhouse doubles as one of the most photographed spots in the nation's capital.

A tribute to the beloved, kind-hearted "homeless mayor" of Silver Spring.

Live data is transmitted from the Atlantic coast to instantly recreate the ocean waves in this fountain at the NOAA headquarters.

Hidden within an idyllic suburban garden is a memorial dedicated to the victims of a terrifying spree of killings committed on U.S. soil.

The longest escalator in the Western Hemisphere takes over three minutes to ride down.

A haunting tribute to pioneering photographer Clover Adams.

A memorial to a shareholder activist feared by CEOs around the United States.

This American Civil War-era fort still stands near the border between Washington, D.C. and Maryland.

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

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

The school tested mustard gas for the U.S. Army during World War I.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

The first presidential bomb shelter was located in an old vault under the Treasury, connected to the White House via tunnel.

A building shaped like the Army Corps of Engineers logo, because why not?

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

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

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

An echo chamber with a waterfall wrapped around its base at the Embassy of Canada in Washington, D.C.

Corn-inthian columns with a uniquely American take on neoclassical architecture.