The mass grave of the 27 victims of the "Vampire of Hanover."

This unique Renaissance castle was turned into a home for Nazi occultism.

Wooden pathways run through this rocky landscape, which legend says was created when a dwarven king pulled down his own castle to stop raiding giants.

An industrial relic is now one of Europe's most staggering art spaces.

No need to strap in for a “ride” on this walkable roller coaster.

This building once stood at the center of a butter war.

This residence straddles a border between Belgium and the Netherlands.

A reconstructed World War I-era communications array that was once hidden in plain sight.

Not many houses move across borders, this one did it twice.

A maze of crosses marks the jumbled divide between the Netherlands and Belgium.

A tribute to smugglers and the Butter Wars.

Relics from as far back as the 16th century are on display in a city known for its playing card industry.

This narrow Ghent alleyway is an officially sanctioned street art tunnel.

A Museum of Psychiatry in a still-operating mental institution.

This monumental mural crafted nearly 40 years ago is still in perfect condition.

This triumphal arch celebrating the Sun King's conquest of Lille is a masterpiece of military architecture.

An astounding collection of taxidermy, fossils, skeletons, and even a few strange live beasts.

These crumbling Nazi artillery bunkers are now fair game for massive graffiti projects.

An anti-tank graveyard in the English countryside.

A reportedly haunted 14th-century church is curiously facing the “wrong direction.”

Vast fan-shaped British cemetery honouring American servicemen lost in World War II.

This 12th-century house is one of the oldest continuously inhabited houses in Britain.

A 4,000-year-old burial site hides behind a roadside Burger King.

A 26-foot shark sculpture—a statement about bombs—set off a municipal battle royale.