Avernus in Wikipedia

Avernus was an ancient name for a crater near Cumae (Cuma), Italy, in the Region of Campania west of Naples. It is approximately 2 miles in circumference. Within the crater is Lake Avernus (Lago d'Averno).[1] Avernus was believed to be the entrance to the underworld, and is portrayed as such in the Aeneid of Virgil. The name is coming from the greek word "αερνος", meaning without birds, because according to tradition all birds flying over the lake were destined to fall dead. In later times, the word was simply an alternate name for the underworld...