One of Jeff Koons’s largest sculptures and his first commemorative work.

The storefront of a ramshackle Parisian puppet theater.

This lesser-known Frank Gehry building houses a treasure trove of cinema history.

The final resting place of the "father of special effects."

A mud statue stands in the dark tunnels, seeming to hold up the weight of the city above.

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

The narrowest street in Paris.

Skeletons, medical artifacts, and other obscure and precious treasures all displayed in a wooden pharmacist's cabinet.

The curious underground history of keeping Paris clean.

This Parisian fountain is a little bit fantasy and a little bit nightclub.

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

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

Egyptian Revival movie palace abandoned for decades and restored in 2013.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

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

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the century.

A counter-culture bookstore like no other hides in plain sight in the streets of Paris.

A haunting collection of the vanished and disappearing natural world.

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

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.