Also known as the Founding Church of Scientology.

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

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

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

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

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

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

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

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

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

This nine-story building is the oldest standing skyscraper in D.C.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

Art deco landmark on the outskirts of Washington, D.C.

The privately owned cemetery that holds room for Washington's finest when they step down from life.

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

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

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

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

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

The national park was once a plantation estate.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.