Read between the lines of the subway map to find the hidden abandoned Civil War fort.

Though its celestial ceiling is impressive, the true star is the vast collection of French books.

Unlock the secrets of the conjuring arts.

Behind a bodega is a small museum of relics and ephemera showcasing the history of New York.

A popular European tradition makes its way to the states on one of America's most famous bridges.

Home to the infamous "Typhoid Mary" and the worst loss of life in New York's history prior to September 11, 2001.

First a horse rendering plant, then a 19th century landfill, this beach is full of glass from thousands upon thousands of broken bottles.

The haunting, dilapidated remains of a former poorhouse on Staten Island's Greenbelt.

From scholastic to sepulchral - now under reconstruction.

The oldest surviving synagogue in New York City is now a soaring art space.

A masterpiece of LGBT art has been restored in what may now be the most valuable restroom in America.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

A very classy 1920s-era bar right in Grand Central Station.

Peek through the gates at this oasis from the city, full of Old English charm.

The world's oldest hologram gallery and the labyrinthine laser laboratory of a holography pioneer.

Mysterious 500-year-old tapestries depict a unicorn hunt.

A DIY art gallery/music venue/lecture hall dedicated to video game culture.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

A celebration of capitalism in Midtown.

A legendary speakeasy bookstore returns from the brink.

A tunnel once abandoned now thrives with graffiti art as an off-limits makeshift gallery.

A hands-on traveling collection of the innovative devices of yesteryear.

Hidden in an ordinary Midtown building is a one-room museum dedicated to the greatest escape artist.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.