A simple plaque on the facade is the only reminder that the treaty ending the American Revolution was signed inside.

This 18th-century sundial was designed to calculate the date of Easter each year.

An unusual number plate signifies the building's saucy past.

The celebrated eyesore created by starry-eyed sweethearts.

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

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

The narrowest street in Paris.

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

The video game-themed street art first popped up in the French city.

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

The remains of the medieval wall that once surrounded Paris with ties to the construction of the Louvre.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

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

A haunting collection of the vanished and disappearing natural world.

A majestic lion statue guards this Parisian botanical garden, and feeds on an unsettling item.

Hidden away in a modern library are the remains of one of the 18th century's most celebrated wunderkammers.

This recessed garden protects thousands of mountain plants by creating its own microclimates.

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

A gruesome combat between a hunter and a furious momma bear.

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

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

The historic Masonic Lodge in which the first-ever female Mason was initiated.

After immigrating to Paris in the 1970s, two brothers from Laos built a grocery store empire.

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