The origin of this mechanical boy was a mystery until he revealed his maker by writing it in perfect cursive.

A daily replay of the experiment that proved the rotation of the Earth.

This elaborate towering structure was once famed for its revolutionary height.

This recreation of a 19th-century dime museum is full of oddities.

The rogue roots are gradually consuming some of the historic marble grave markers.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

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

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

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

Daredevil repair workers can worm their way out the access hatch, loop ropes over the apex and rappel down the monument.

Look closely and you’ll notice that the color changes a third of the way up the tower.

A computer bug so primitive it was an actual insect.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

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

This taxidermy horse was a Civil War hero.

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

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

Washington's iconic carousel has a nice piece of Civil Rights history.

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

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

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

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

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