From Yahoo Travel:

Capuchin Cemetery

Long after all the rest of Rome’s interiors run together in the memory, visitors vividly recall the particulars of these bizarre and macabre chapels, where the decorative elements are all made of human bones.

Between 1528 and 1870, the brown-clad Capuchin monks adorned this cemetery with the dried remains of their departed brothers. The message is appropriately pious: ‘What you are now we used to be, what we are now you will be’. The effect is rather sensational.

There is an arch crafted from hundreds of skulls, vertebrae used as fleurs-de-lis, and light fixtures made of limb bones.