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

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

Visit the monolithic tomb of America's most famous general.

A bit of retro transportation flair preserved in the world's largest department store.

Spinning silently in the lobby of an Art Deco masterwork is a massive vintage model of the Earth.

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

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

The only home that Alexander Hamilton ever owned has a history almost as troubled as his own.

A Manhattan courthouse hides a small but scathing memorial to Holocaust injustice.

Bowl in splendor, if you're lucky.

The walls are decorated with whimsical murals painted by the creator of the Madeline franchise.

Plot your trip through the city on the sidewalk.

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

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

The oldest house in Manhattan is now a museum that remembers the home's sordid history of scandals, vice-presidents, and ghosts.

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

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

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

Walk over a 150 year old manhole.

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

One of the last Jazz Age "Wonder Theaters" in New York City.

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

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

One of the last few places in Manhattan that employed a pneumatic systemic keeps it on display.