One man's personal kunstkammer, museum and shop.

A peculiar family mausoleum built by a German nobleman captivated by the occult.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

The site of the first battle of World War II.

Europe's second largest ossuary wasn't discovered until 2001.

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

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

Local lore says the devil built this beautiful medieval bridge to help a fleeing bandit.

The beautiful baroque library of the Hapsburg empire.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

On the Irish coast, 18 members of the Howard family are eternally resting in an Egyptian pyramid.

A collection of collections, including an anatomy museum, the “Cabinet of Physics of Alessandro Volta, a museum of natural history, mineral collection, and much much more...

Wax models of disease and deformity are on display at this German medical museum.

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

A rococo room covered entirely in porcelain originally constructed for another royal residence.

An underground paleo-Christian burial site composed of the remains of several cemeteries and Basilicas.

The burial place of an obscure North African saint was turned into a macabre body preservation factory for the 17th-century Neapolitan elite.

These 12th-century catacombs carved into a mountainside were a place of mysticism and Christian hermitages.

Naturally preserved bodies are eerily staged throughout the crypt in varying poses.

Eight naturally mummified bodies in glass coffins are housed in an underground crypt.

The bones of some 7,000 soldiers killed in the historic Battle of Solferino are stored here.

This landmark church concealed a crypt packed with bones that was discovered thanks to the London Blitz.