D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

Over the last century, this elegant columned facade has been home to the headquarters of a bank, several nightclubs, and a restaurant.

This Masonic lodge was the first major private building to be constructed in Washington, D.C. after the Civil War.

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

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

Before founding the American Red Cross, Clara Barton had a tremendous humanitarian impact by locating thousands of missing soldiers.

Go take a picture with the inventor of the daguerreotype photographic process.

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

A much-maligned monument to teetotalism.

It was once the base for a series of domestic terror attacks.

An echo chamber with a waterfall wrapped around its base at the Embassy of Canada in Washington, D.C.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

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

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

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

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

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

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

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

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.

The National Park Service’s best-kept secret with views that rival any in D.C.

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