The only female equestrian statue in Washington, D.C. is a 15th-century French heroine.

This rowhouse doubles as one of the most photographed spots in the nation's capital.

Disks are rolled out onto the south lawn to absorb the impact of Marine One's wheels like giant coffee coasters.

An obscure federal monument honors the French diplomat who served as Ambassador to the U.S. during WWI.

Through the decades, Black music stars have performed at this historic hub for music and the arts.

This statue honors the author's groundbreaking family story.

One of the last mosaic tile facades found in the city.

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

D.C. once had its own tiny rival to the New York Stock Exchange.

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

A commemorative plaque hides a door that leads down to the New York Public Library's underground book bunker.

Established in 1937, the oldest candy shop in New York City boasts a rainbow-colored inventory that would make Willy Wonka envious.

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

A remnant of the original World Trade Center complex continues to serve as a commuter gateway.

Built hundreds of years ago this downtown iron barrier once protected a much despised king.

An abandoned asylum once on the cutting edge of lobotomies may be reborn as a Christian college.

The largest Buddha statue in the Western Hemisphere is just 50 miles north of NYC.

The oldest continuously inhabited street in America.

The only intersection in America where the buildings on all four corners were built pre-Revolutionary War.

This mouldering abandoned mental hospital was once a center for progressive healing.

This sound-art installation features songs composed using only the Mid-Hudson Bridge as an instrument.

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

Beneath unsuspecting visitors feet, a capsule containing pieces of America’s civil rights history.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.