This German bone house contains the remains of some 20,000 souls.

The remains of 40,000 humans, meticulously stacked in a tiny churchyard shed.

This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

It's always summer at the beach inside this former airship hangar.

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

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

One of the deepest indoor swimming pools in the world.

A Belgian self-built tower inspired by the Bible and ancient civilizations.

This fairy tale forest hides scenes from some of the more obscure and bizarre Western nursery stories.

A true Valhalla for cactus and succulent lovers.

The birthplace of most all of Europe's space missions is here on the Dutch coast.

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

Take a walk in a recreation of ancient Rome.

A former plague hospital turned medical museum.

The giant scales in this museum can still tell if someone is one of the devil's brides just by weight.

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

A historic observatory now an astronomy museum beautifully situated at the moat of the Middle Age city centre.

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

Cat art as far as the eye can see.

Museum preserving torture methods from the past.

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

A monument hidden in the woods built in 1938 as a getaway for a Dutch museum curator.

Home to the world's oldest functioning orrery.

A bizarre form of natural mummification was discovered in the church of this Frisian village.