Elevated freight railway turned wildly successful urban park.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

Art from the latest counter-culture; kids who dye their hair blue and believe the future will be a post-apocalyptic water world.

A huge musical instrument played by the ocean.

An artsy hidden staircase leads to breathtaking views of San Francisco.

The bank that helped fund the Mexican-American War and the purchase of Alaska met its downfall after helping Augusto Pinochet launder money.

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

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

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

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

Part of a WWII submarine is lurking outside the Washington Navy Yard parking lot.

Also known as the Founding Church of Scientology.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

The first memorial dedicated solely to the Black troops who fought for the Union.

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

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

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

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

100 years later, they're still down there.

This restaurant has been a haven for D.C.'s LGBTQ community since the 1950s.

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

An easily overlooked memorial to a Ukrainian famine-genocide that killed over 4 million people.