This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

This semi-hidden Manhattan restaurant is based out of a loading dock.

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

A WWI fighter plane and turn-of-the-century penny candy shop are among the unexpected features of this Financial District building.

For over 30 years the walls of this Harlem schoolyard have been a gallery of street art by "Kings and better."

Prove you deserve to be fed by Kenny Shopsin.

A hidden "place of interment for gentlemen."

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

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

Walk over a 150 year old manhole.

Great place to have a drink and a bite to eat in an atmosphere laden with New York's Bohemian past.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Once the tallest building in the world and the site of "the highest dinner ever held in New York" this building now holds the most expensive penthouse in the city.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

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

From scholastic to sepulchral - now under reconstruction.

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

An unassuming secret door once led to a legendary watering hole.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

This unmarked and unloved Manhattan subway grate created one of the most iconic images in American cinema.

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

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

One of only two commuter aerial tramways in the United States.