Naples is the city built over different kinds of caves. These are not only catacombs but passes, aqueducts, other holes. Some of them are opened for the visits but the most spectacular are without doubts catacombs and charnel grounds. I wrote about one of them in one of my previous posts (Catacombs of Naples - San Gennaro Catacombs ). Here are some words about an other place you can visit - cemetery of Fontanelle where bones of the persons dead during different plagues so frequent in centuries of the history of Naples are collected. They guess, there are bones of 40 000 persons in this cave actually. But those are only those found on the ground. Many of them were buried under the actual floor.
Residents "adopt" sculls, carry about them and ask them to help to solve their problems. And, this belief is alive today, too, the deceased really help.