This speakeasy continues the Prohibition-era legacy of Harlem's jazzy Swing Street.

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

NYC's legendary underground network for bovine transportation.

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

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

Rare moles meet activism at this Oaxacan eatery.

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

A Manhattan Episcopal church with an eerie underground crypt.

This hidden library of physiological ephemera contains centuries worth of knowledge on the vim and viscera of the human body.

A memorial marks the library lobby where Langston Hughes' ashes are buried.

A once crucial portion of the Long Island railroad still lays abandoned, waiting to be turned into an urban park.

These historic buildings once housed the headquarters of one of the most infamous gangs of New York.

New York City's only preserved family home from the 19th century.

The first piece of public art dedicated to LGBT rights.

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

The oldest operating apothecary in the US has treated everyone from Thomas Edison to Mark Twain.

The world's largest collection of materials relating to lesbian history is housed in a Brooklyn townhouse.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

During the holidays, a vintage subway train whisks New Yorkers back in time.

A crumbling hospital from the 1850s on Roosevelt Island.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

This quirky museum will make you question everything, including the shape of the planet.

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

A herd of colorfully painted bovine statues can be found in the middle of "cowtown."