This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

A crumbling hospital from the 1850s on Roosevelt Island.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

An annual extravaganza of Broadway theater memorabilia.

A way to take your secrets to someone else's grave.

Thriving meadows span a rooftop in one of Brooklyn's most heavily industrialized neighborhoods.

A prized globe signed by Amelia Earhart and Charles Lindbergh sits in the Brooklyn office of the American Geographical Society.

A replica of a 7th-century church hides in plain sight in the middle of the concrete jungle.

A beautiful collection of architectural ornaments rescued from demolished New York City buildings.

The last living thing to come out of the rubble after 9/11 is now a symbol of hope and resilience.

A mysterious, abandoned building rotting on the Brooklyn waterfront.

A young woman's senseless murder led to the controversial psychological theory of the "bystander effect."

New York City's only radical feminist independent bookstore.

Historical figures from New York City's Catholic community reside in Midtown.

An exhibition space dedicated to American outsider art created between the 18th and 21st centuries.

This secluded ruin was once a home for exotic plants.

The highest rapid transit station in the world.

You must take the A train... to the last active cemetery in Manhattan.

This hidden oasis features a stunning view of the Hudson River and the Palisades from a castle-like museum.

Nearly four centuries after its founding, remnants of one of the oldest planned communities in North America are still visible in southern Brooklyn.

Devotional offerings and pleas for intercession are left at this Depression-era shrine inside a nature preserve.

This eclectic sculpture garden in Brooklyn, home to a bizarre collection of art, was once a run-down junkyard.

Empty, but not abandoned, this cavernous Brooklyn loading dock was once considered the largest individual building in the world.