The preamble to the U.S. Constitution written entirely from vanity license plates hangs in the Smithsonian museum.

A surprising, but overlooked example of geology in the middle of the nation’s capital.

A cave on the Maryland border where civilians took refuge during the bloodiest battle of the Civil War.

Bizarre Cavern.

Home of the physician who set the leg of John Wilkes Booth after the Lincoln assassination.

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

This colonial tavern played host to George Washington, Thomas Jefferson, and other famous early Americans.

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

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

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

There’s a hidden military meme engraved on the World War II Memorial.

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

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

A computer bug so primitive it was an actual insect.

A historic neighborhood church is reborn as a psychedelic arts collective.

A painfully obvious spy house sits right across the street from the Russian Embassy.

The "lovely red Vega" of the legendary record-settling pilot.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

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

The first memorial dedicated solely to the Black troops who fought for the Union.

Walk a trail through a historic Quaker town that outlawed slavery in 1777 and was a major waypoint on the Underground Railroad.

This free, take-a-book shop seems like a trick but isn't.

A hidden alley in urban Baltimore is a haven for graffiti artists.

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