The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.

Hop aboard a charming bog train to explore this rare open-air museum of peat.

This towering church is home to a world-famous organ and a treasure trove of medieval art.

Mosaics created from 11 million cigar bands.

Lombardy poplars planted to imitate the size and shape of the Cathedral of Notre-Dame de Reims.

Devious political maneuvering and four ancient, working telescopes are central to the world's second-oldest observatory.

A dream-like maze full of strange art, surreal spaces, and fantasy landscapes to get lost in.

A seven-century-old jail tells a not-so-pleasant history of crime and punishment.

The world's first interactive human body museum also serves as a chair for a giant orange man.

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

A market built atop boats is one of the few floating holiday markets in Europe.

This centuries-old gothic monster has been converted into a sprawling, glossy bookstore.

A unique collection of gilded age mechanical pianos.

A former plague hospital turned medical museum.

Oldest Museum of the Netherlands is a true cabinet of curiosities.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

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

Museum preserving torture methods from the past.

A floating cat sanctuary on an Amsterdam canal.

Cat art as far as the eye can see.

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

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.