Santa Maria della Concezione dei Cappuccini, or Our Lady of the Conception of the Capuchins, is a church in Rome, Italy, commissioned in 1626 by Pope Urban VIII.

The crypt is located just under the church. Cardinal Antonio Barberini, who was a member of the Capuchin order, in 1631 ordered the remains of thousands of Capuchin friars exhumed and transferred from the friary Via dei Lucchesi to the crypt. The bones were arranged along the walls, and the friars began to bury their own dead here, as well as the bodies of poor Romans.

Some of the skeletons are intact and draped with Franciscan habits, but for the most part, individual bones are used to create elaborate ornamental designs.

Photo by Paul Koudounaris in his Empire de la Mort.
Quoted text via Wikipedia.