A memorial dedicated to the famed North Pole explorer appropriately sits at the far edge of Arlington National Cemetery.

Right next to departures—how convenient!

Mass grave of 50 unidentified French Soldiers who died at the Siege of Yorktown, 1781, that gave victory to the American Revolution.

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

The Pentagon sits on a former island that was in Virginia at low tide and D.C. at high tide.

This unique structure is the only one of its kind in Virginia.

The remains of a historic plantation nestled in between a parking lot and the rental car return at Reagan National Airport.

The resting place of a Civil War celebrity's amputated limb.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

A computer bug so primitive it was an actual insect.

The 28,000-year-old specimen is remarkably intact.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

The story behind this beloved toy—named for Theodore Roosevelt and owned by his grandson—is more complicated than you might guess.

The most decorated dog of World War I is preserved in the Smithsonian.

Perhaps the most scandalous statue of America's first president.

This taxidermy horse was a Civil War hero.

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

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

Railroad officials in the early 1900s sought to spare travelers the sight of Roman soldiers’ private parts.

National Mall monument to the inventor of the screw propeller.

The U.S. Fish Commission’s effort to mass produce carp.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

A much-maligned monument to teetotalism.