The Capuchins were an austere group of monks established in 1529. To ensure a proper resurrection, they saved everything including the bones of 4000 monks when they died, and until 1870, decorated four small crypt chapels to construct Rome’s strangest site.
Each chapel has a theme – skulls, pelvises, thigh-bones, leg bones – stacked (think the Paris catacombs) and used to make arches and altars displaying clothed skeletons.
Skeletons of small children and the small bones (jaws, vertebrae, feet and hands) are used to make light fixtures, picture frames and elaborate decorations covering the walls and ceilings. It is very well done and almost attractive in a macabre way.
First pass through a multimedia museum explaining everything you would want to know about the Capuchins.