Those belting out show tunes might not realize this piano bar marks the site where Thomas Paine died in 1809.

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

Nikola Tesla's former home contains an homage hidden from plain sight.

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

A legendary speakeasy bookstore returns from the brink.

The New York hotel where tragic visionary Nikola Tesla spent his final hours, destitute and alone but for the pigeons.

The beautiful tunnel that ran from the lobby to Penn Station is still hidden underneath 34th Street.

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

New York City's first Modernist house.

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

The original toys that inspired the beloved children's stories are on display at the New York Public Library.

Built as a gift to the hottest tastemaker of the time, these hidden quarters remain an Art Deco showpiece.

Read a book next to a Midtown waterfall.

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

Finally, you don't have to be a pious Swedish seaman to relax like one.

This tiny store is your one-stop shop for all sorts of rare and wonderful buttons.

The oldest bibliophilia club in America, with exhibitions on historic books and graphic arts.

A small piece of the composer's New York home lives on in the center of Czech culture in Manhattan.

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

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

New York's oldest and possibly grandest keeper of books.

The front yard of an Upper East Side town house hides the last fragment of one of New York's most famous theatres.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

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