Right at the end of the winding Via Fontanelle, this old Greco-Roman tuff quarry houses thousands of bones belonging to the victims of the 17C plague, which killed 300 000 Neapolitans. Made famous by the Rossellini film Voyage to Italy (1953), the vast cave with three long aisles is lined with skulls. Opened to the public in the 19C, the ossuary was used for the anime pezzentelle (abandoned souls) or capuzzelle (small heads) cult, which was banned by the Church in 1969.