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

Two awe-inspiring globes from the reign of the Sun King hang from the ceiling of France's national library.

An off-the-beaten-path boutique stuffed with an eclectic collection of upcycled goods.

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

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

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

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

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

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

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

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

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

A surrealist timepiece by the artist of melting clocks.

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

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

An eclectic art form practiced by untrained masters is celebrated at this museum in the heart of Zagreb's old Upper Town.

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.