The Capuchin Crypt in Rome

The Capuchin Crypt is a small space comprising several tiny chapels located beneath the church of Santa Maria della Concezione dei Cappuccini on the Via Veneto near Piazza Barberini in Rome, Italy. It contains the skeletal remains of 4,000 bodies believed to be Capuchin friars buried by their order. The Catholic order insists that the display is not meant to be macabre, but a silent reminder of the swift passage of life on Earth. There are six total rooms in the crypt, five featuring a unique display of human bones believed to have been taken from the bodies of friars who had died between 1528 and 1870.

Described by Frommer's as "one of the most horrifying images in all of Christendom", large numbers of the bones are nailed to the walls in intricate patterns, many are piled high among countless others, while others hang from the ceiling as light fixtures. (wikipedia)