Phlegraean Fields

The Phlegraean Fields is a large volcanic caldera situated to the west of Naples, Italy. It is part of the Campanian volcanic arc, which includes Mount Vesuvius on the east side of Naples. The Phlegraean Fields is monitored by the Vesuvius Observatory. It was declared a regional park in 2003.

The area of the caldera consists of 24 craters and volcanic edifices; most of them lie under the Bay of Naples. There are effusive gaseous manifestations in the Solfatara crater, which was regarded in ancient times as the mythological home of Vulcan, the Roman god of fire. The area features bradyseismic phenomena, which are most evident at the Macellum of Pozzuoli: bands of boreholes left by marine molluscs on marble columns show that the level of the site in relation to sea level has varied. Hydrothermal activity can still be observed at Lucrino, Agnano and the town of Pozzuoli.