Agnano Caldera
Part of The Encyclopedia of Southern Italy.
Agnano Caldera (Lago di Agnano): A volcanic crater (6.5 km in circumference) in the Phlegraean Fields, located to the NW of Naples. The Greeks and the Romans enjoyed visiting the local hot springs and believed that witches inhabited the region. By medieval times the crater had filled with water to become a malarial lake, remaining so until finally being drained in 1870 through a tunnel at its SW edge. The recovered land was used for a time for cultivation of crops and is now the site of the Agnano hippodrome and some hotels. At the S rim of the crater is Agnano Terme, a health spa.
The crater is the site of the Grotta del Cane (Cave of the Dog). In times past local guides would demonstrate the existence of the deadly carbonic acid gas in this cave by exposing a dog to them.
To the E of Agnano caldera is the Parco degli Astroni, another extinct volcano.