Haunting graffiti left by prisoners of the Spanish Inquisition.

Wax models of disease and deformity are on display at this German medical museum.

The curious underground history of keeping Paris clean.

Stroll through retro Paris while shopping for old postcards and discarded doll heads.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

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

Got apples?

This banal Parisian entranceway is not what it seems.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

The oldest stone house in Paris was built by its most famous alchemist.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

This giant, 83-year-old ship elevator is an engineering feat to behold.

The world's most delightful not-NOT-religion welcomes visitors to the town of Templin, just like its more stoic peers.

Two stunning 17th-century libraries and a cabinet of curiosities.