1. Introduction . Two of the most famous and high-risk volcanoes in the world, the Somma–Vesuvius and the Campi Flegrei caldera, overlook the Gulfs of Naples and Pozzuoli. Ischia island, the third active volcano of the Neapolitan volcanic area, is located at the north of the Gulf of Naples and a short distance from the Procida island.The Campi Flegrei caldera (CFc) is an active volcanic system located to the west of the city of Naples. This whole area, with about 1.5 million inhabitant...