 The second level was the one expanded so as to encompass the other two adjacent cemeteries.The foundation of San Gennaro extra Moenia is connected with the Catacombs of San Gennaro, the largest Christian catacomb complex in southern Italy.The first structure was probably the result of the fusion of two ancient burial sites, one from the 2nd century CE that contained the remains of Saint Agrippinus of Naples, the first patron saint of Naples, and the site from the 4th century CE that contained the remains of St. Januarius, the patron saint of the city.