This speakeasy continues the Prohibition-era legacy of Harlem's jazzy Swing Street.

This lavish room at NYC's French Embassy is a rare relic from the end of the Gilded Age.

A staggering collection of photographs depicting medical, social, and historical change.

Hidden in one of New York's oldest subway stations is the final remnant of the site of the bizarre Shakespeare Riots.

The iconic Manhattan corner that was once the site of the Beastie Boys' fake clothing store.

Relics given to a Manhattan church to avoid seizure by the Italian government.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

America's oldest Eastern European synagogue provided the immigrants of crowded Lower East Side tenements a space of sanctuary.

A hidden "place of interment for gentlemen."

Touching mementoes from those who didn't make it back from World War I still hang in one of New York's oldest bars.

A whimsical, but often overlooked clock in Park Avenue.

A small peaceful park and waterfall tucked amid the urban grind of Midtown Manhattan.

A curious fountain that has no water and includes Satan, a crab, and 9 giraffes.

New York City's only radical feminist independent bookstore.

The first museum in the United States dedicated entirely to posters.

One of the last full-orchestra recording studios in New York City and an acoustical marvel.

A historic 1890s architectural masterpiece with an iconic clock tower that, once open to the public, now faces an uncertain future.

Have a steam and some blini at this cafe in a century-old bathhouse.

New York City's only preserved family home from the 19th century.

Unrepaired walls from a 1920 anarchist bomb attack.

Cryptic messages embedded in the New York City sidewalk.

The name of this tiny pocket park tucked between two buildings on Manhattan's Upper West Side is Latin for its location: "seventy-one."

This wall on a street corner in Lower Manhattan has been a blank canvas for a rotation of renowned artists since the 1980s.