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

This grisly headstone doesn’t seem to be resting in peace.

When it comes to handsignals (and colonialism) rock always beats scissors.

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

Before Nixon, "watergate" meant canals.

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

The most accurate timepiece in the world.

Largest Roman Catholic church in North America.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

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

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

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

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

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

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.

An obscure public service from the U.S. government that redeems burnt, moldy, and soiled old greenbacks.

For 60 years, the academy had no permanent location until members voted Washington D.C. as its forever home.

The oldest continuously operating fish market in the United States.

Decades before the scandal, this staircase on the river was a literal "water gate."

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

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

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

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