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

NYC's legendary underground network for bovine transportation.

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

Named the fifth most beautiful building in America in 1885, this former courthouse boasts the best view in the Village.

A legendary speakeasy bookstore returns from the brink.

Wine bottle sculpture with a ship's stateroom inside.

In the best of all possible worlds, everyone will get a chance to see this statue in which Voltaire's heart is interred.

The floorboard scrawling of a tragic madman is on public display outside a Paris hospital, much to the dismay of its opponents.

The Sun King's military models, saved from the Louvre.

The personal library of the founder of modern neurology is open to visitors.

The former home of France's controversial pop maestro is almost completely covered in ever-changing tributes and graffiti.

Natural history museum celebrating biodiversity with a parade of taxidermy animals.

Pitié-Salpêtrière was the dumping grounds for women who received the dreaded diagnosis of "hysterical."

Down a cobblestone alleyway is a museum dedicated to Romanticism, with a secret garden.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

Architectural monsters are devouring this palace's every door and window.

This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

The underground sanctuary of a mysterious ancient cult.

The former hotel where Tesla invented the radio.

This Fifth Avenue church has long been the favored worshiping place of Broadway actors and vaudeville performers.

This former Norwegian sailor's church is slowly being taken over by ramshackle robot musicians.

Unlock the secrets of the conjuring arts.

Historic Greenpoint theater, turned roller disco, now housing a chain pharmacy store.

A pub that is literally in the middle of nowhere, but continues to do business.