Avernus was an ancient name for a volcanic crater near Cumae (Cuma), Italy, in the region of Campania west of Naples. Part of the Phlegraean Fields of volcanoes,[1] Avernus is approximately 3.2 kilometres (2.0 mi) in circumference. Within the crater is Lake Avernus (Lago d'Averno).[2]
[in the chart] Campi Flegrei [...] Averno