Capuchins’ Catacombs (Palermo, Italy)

In 1599, Capuchin monks made a shocking discovery while exhuming bodies from the catacombs of their monastery — many of the bodies had been naturally mummified. Following this discovery, the monks decided to mummify one of their own, and the Palermo townspeople soon joined in. Deceased members from all social classes were mummified and placed in these catacombs until the 1880s, when the practice of mummification was banned. But that didn’t stop the curious townspeople, as the last mummy was laid to rest here in 1920. As a result of this “mummification trend,” the catacombs of the Capuchin Monastery have become one of the largest, and most eerie, collections of mummified bodies in the world.
Thanks to Carolyn for the suggestion.