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

Outside the Department of Transportation, a collection of artifacts honors the history of how we get around.

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

The tunnel under the Capitol Building where Congress takes out its trash.

The grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

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

A tribute to the pop culture icon overlooks this Washington D.C. intersection.

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

The hidden offices underneath Memorial Bridge have been locked up since 1976.

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

Government testing at the asylum briefly explored using marijuana as a "truth serum" on Nazi prisoners of war.

A historic neighborhood church is reborn as a psychedelic arts collective.

A street in front of NASA's D.C. headquarters has been named in honor of the Black women who were essential to early spaceflight.

Washington D.C.'s most famous pianist, composer, and bandleader still tickles the ivories outside Howard Theater.

The world's oldest soul food restaurant is also one of its best.

The neighborhood of Eagle Rock is named after a gigantic boulder with a shadowy surprise.

A black and white mural stands out from its psychedelic surroundings.

The blinking light atop the iconic landmark has been sending secret messages for decades.

A secret greenspace hides atop a Capitol parking garage.

Behind an abandoned storefront is an example of pioneering 1930s gas station architecture.

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

An unassuming, powerful monument north of the U.S. Capitol bears witness to the resilience of Japanese Americans during a time of grave injustice.

The most accurate timepiece in the world.

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