The largest body of water in Massachusetts annihilated four small towns just to slake Boston's thirst.

A glimpse into early 19th-century education.

This former Cold War missile control site played an important role in the creation of GPS.

An out-of-place Air Force radar dome is all that denotes this park as a former missile launch site.

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

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

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

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

An oft-overlooked, magically musical monolith that stands majestically between Arlington Cemetery and the Iwo Jima Memorial.

The tunnel under the Capitol Building where Congress takes out its trash.

After his presidency, George Washington planned to live only a few blocks from the Capitol building.

Outside the Department of Transportation, a collection of artifacts honors the history of how we get around.

The Pentagon is so large that it was planned like a city, complete with internal highway infrastructure.

Before founding the American Red Cross, Clara Barton had a tremendous humanitarian impact by locating thousands of missing soldiers.

The iconic D.C. restaurant where the Cuban Missile Crisis was negotiated, now a Walgreens.

Before Nixon, "watergate" meant canals.

An unassuming, powerful monument north of the U.S. Capitol bears witness to the resilience of Japanese Americans during a time of grave injustice.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

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

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

The word "Watergate" will forever be associated with the infamous scandal in 1972, but this fountain is famous in its own right.

This church built atop a gas station promises to "equip you for the next stage in your life’s journey."

Parking garage where Bob Woodward met Watergate source "Deep Throat."

The span is crooked and made from two older recycled bridges.