Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

Also known as the Founding Church of Scientology.

This apartment building designed by a notable Washington D.C. architect housed the Qing Dynasty's Legation.

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

The oldest house in Washington, D.C. wasn't originally constructed in the nation's capital.

A public art jibe at one of the United States’ oldest and longest-serving senators.

People escaping slavery may have hidden inside a corpse vault.

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

An overlooked tribute to one of the most important peace deals in American history.

The 320-year-old tree that greeted General Lafayette and rerouted an interstate highway.

Once a sewer culvert, this road tunnel now offers cyclists and pedestrians a subterranean stroll under the C&O Canal.

The word "Watergate" will forever be associated with the infamous scandal in 1972, but this fountain is famous in its own right.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

A Spiritualist house of worship where believers communicate with the dead in the spirit world.

‘Bush the old fire dog died of poison July 5th, 1869. RIP.’

A small token of gratitude from freezing cold journalists who were given a warm haven while covering JFK's inauguration.

An eponymous directional signpost erected by the first president of the United States.

This suburban house is made of dirt, and almost sparked a revolution in home construction.

Housing the National Women's Party since 1929, this historic house is now a monument to the fight for gender equality.

Railroad officials in the early 1900s sought to spare travelers the sight of Roman soldiers’ private parts.

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

A diminutive memorial marks the site of a successful assassination by a right-wing death squad in America's capital.

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