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

This taxidermy horse was a Civil War hero.

A computer bug so primitive it was an actual insect.

The innocent intentions of this monument are somewhat lost in the sculpture's muscled imagery.

A line of blue paint marks the route of the inaugural parade.

Disks are rolled out onto the south lawn to absorb the impact of Marine One's wheels like giant coffee coasters.

There's an old indoor swimming pool hidden directly underneath the White House Press Briefing Room.

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

D.C. once had its own tiny rival to the New York Stock Exchange.

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

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

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

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

This unassuming passageway played a key role in one of the most important events in U.S. history.

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

The sculptor was instructed to add “stallion attributes” to the general's bronze mare.

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

One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

Four bald cypress trees in Lafayette Square, across from the White House, mark the southern edge of a 100,000 year old cypress swamp.

A replica of the famous memorial statue at the Normandy American Cemetery hides in an office building in downtown D.C.

Where the U.S. government kept its actual treasure, before Fort Knox.

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

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