What looks like a normal building is really a hollow facade hiding a subway vent.

Despite being considered a thoroughly American sport, basketball's oldest surviving playing field is found in the basement of a Paris YMCA.

The headless bodies of more than 1,300 guillotined victims of the Reign of Terror are buried here in mass graves.

This Paris art space celebrates the creativity and ingenuity that springs from abject poverty, especially in Africa.

This museum in a Paris apartment gives a unique look at the iconic French singer's life.

The recovered bones of martyrs slaughtered during The Terror are on display in this church crypt.

This off-limits room in the National Library of France is home to a system of pneumatic tubes, once used to bring books to readers.

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

The subterranean "lake" below the Paris opera house inspired the Phantom of the Opera's lair.

Paris' fabled purveyor of exotic taxidermy and natural history curios.

The history of radiation is on safe display at the foot of a radiation science laboratory.

Known as the "Dodo Manège," this carousel features a herd of animals that have disappeared—or may be gone soon.

A museum on the history of Paris, including a set of Napoleon's toiletries, Proust's room, and relics of the Revolution.

A subterranean shelter remains intact under a busy Paris railway station.

"In the Dark" Restaurant in Paris offers dinner in complete darkness.

This museum houses an imposing skeleton army comprised of creatures great and small.

Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

A haunting collection of the vanished and disappearing natural world.

One of the oldest medical collections in Europe focusing on rare surgical instruments.

A museum of carnival attractions where you are invited to ride the rides.

Abandoned railway line circling the city of Paris.

France's most famous cemetery, with some of its most curious tombs.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

Symbolic attempt to overcome the issues of life.