Mummified monks and the accidentally interred, in a 17th-century crypt.

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

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

Thousands of well-dressed mummies below a monastery.

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

Skulls from the plague of 1656 and World War II bombings are united by a cult dedicated to caring for the ancient dead.

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

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

An Austrian house of bones filled with hundreds of intricately painted skulls.

A church of bones, decorated with 40,000 human skeletons.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

One of the largest ossuaries in Spain is packed from floor to ceiling with bones.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.