Hidden away in a modern library are the remains of one of the 18th century's most celebrated wunderkammers.

In the best of all possible worlds, everyone will get a chance to see this statue in which Voltaire's heart is interred.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the century.

A burial vault located under Tiber Island in the middle of the Italian capital.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

One of the most important yet well-hidden museums dedicated to the history of medicine.

A fairy tale castle in modern Rome.

Architectural monsters are devouring this palace's every door and window.

A museum dedicated to one of Paris’s most famous residents, tucked into a corner of one of the city’s most famous squares.

Notorious artist squat renovated into legal studios.

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

Entire apothecaries are on display at this Lisbon museum, which explores the history of medicine.

Building owners can take out tiles for free at this repository for historic building materials.

A cluster of granite granaries perched on stilts.

This unassuming chapel in Portugal plays host to a ghoulish collection of bones.

The corpse bride of Portugal.

This charming candle shop has been in business since 1789.

This former school is now abandoned and a canvas for graffiti artists.

An underground city of salt.

This hospital once pioneered the use of electroencephalograms, but fell into maltreatment, abuse, and eventual abandonment.

St. Mary's Asylum was isolated and abandoned before being converted into a Bed and Breakfast.

The oldest residential street in Europe also features an optical illusion.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.