This otherwise innocuous bodega was once the headquarters of the most feared assassin's guild in American history.

This abandoned caretaker's apartment is one of 13 left in the New York Public Library system.

A Victorian cemetery in the heart of Brooklyn remains a popular mecca of morbid curiosity.

A dark patch of the ceiling at Grand Central Terminal which was not restored is still stained brown by tobacco.

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

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

A notorious punk house turned co-op.

Salute the leader of the proletariat.

In its day this historic fort held 100 cannons pointed in almost every direction to protect New York.

An odd, ancient window that may have once been part of a brutal prison is embedded in the side of New York's Police Plaza.

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

This enormous Hindu temple in Queens serves incredible dosas in its basement canteen.

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

“Invented in Key West, Perfected in Brooklyn."

Once America's longest-manned military fort, now an abandoned hulk.

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

Volunteer-run library dedicated to exploring five decades of activism history.

A good place to research the Freemasons, esoterica, occultism, and hermeticism.

In the middle of downtown Brooklyn lies a 165 year old secret hidden right below the surface (closed to the public indefinitely).

The famous author's cottage hideaway.

A discreet little stairway on St. Nicholas Avenue leads to a quaint and unexpected cobblestone street of 19th century wooden rowhouses.

Unrepaired walls from a 1920 anarchist bomb attack.

The end of the 4 Line is also the end of the line for 300,000 souls in one of NYC's most illustrious cemeteries.

A quiet and contemplative oasis in the middle of New York's bustle and riot.