Legend has it fairies gathered at the site of this medieval castle.

The complex has been abandoned since the Croatian War of Independence, barring a stint as a set for 'Game of Thrones.'

The remains of a sunken military ship wreck visible through clear water.

A musical instrument played by the sea.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

An ethereal glowing blue ocean cave in Croatia.

It houses the remains of a 17th-century version of the Titanic.

A Netherlands hotel where you can sleep inside a wine barrel.

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

Peek through a transparent pyramid and drink in the mountain made of books.

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

The former home of a mad diplomat is said to still be marked in bloody, arcane scrawls.

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

Museum preserving torture methods from the past.

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

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

The oldest of Venice's plague quarantine stations, designed to keep the medieval city safe from disease.

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

Venice's "Island of the Mad."

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.