A vast cave carved into the tufa hillside of the Materdei district, containing the remains of an estimated 40,000 people — victims of plague, cholera, and famine accumulated over centuries. The Fontanelle is a place of extraordinary strangeness: the skulls and bones are stacked in rows along the cave walls, and many were individually adopted by Neapolitan families who believed in the animelle — the souls of the unremembered dead who could grant favours to those who cared for them.
The cult of the skulls was a uniquely Neapolitan fusion of Catholic and pre-Christian belief. The cave was closed for decades after the Church cracked down on the practice but has been open to visitors since 2010. Admission is free. The walk to Materdei from the Centro Storico takes about 20 minutes; the Salvatore Rosa metro station is nearby.