A grotto-like lodge decorated with gilded mosaics, rocks and a noisy waterfall was the setting for the most sumptuous pleasure house of 1900s Europe.

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

France's national museum of scientific and industrial instruments.

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

A mechanized clock where a man fights off a dragon, crab, and rooster.

Dolls of all shapes and sizes display the eras of femininity in this spooky and beautiful collection.

Notorious artist squat renovated into legal studios.

This little-known relic crypt holds stolen parts of a Roman Empress.

A Parisian exterminator's shop whose storefront displays stuffed rats hanging from traps.

One part local history, 99 parts gruesome haunted house.

Colorful and chaotic stacked hotel in North Holland.

A curious collection dedicated to human and animal anatomy and pathology.

The world's only museum devoted to the wonders of fluorescence.

Amsterdam's Red Light District leaves little to the imagination.

The attic of a four-century-old canal house hides a clandestine church.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

Cat art as far as the eye can see.

A beautifully eclectic mix of architectural styles.