Campi Flegrei

Phlegraean Fields
Campi Flegrei
A NASA space shuttle's photo of the area, with main features labeled
Highest point
Elevation	458 m (1,503 ft)
Coordinates	40°49′37″N 14°08′20″E / 40.827°N 14.139°E / 40.827; 14.139Coordinates: 40°49′37″N 14°08′20″E / 40.827°N 14.139°E / 40.827; 14.139
Geography
Location	Italy
Geology
Age of rock	40,000 years
Mountain type	Caldera
Volcanic arc/belt	Campanian volcanic arc
Last eruption	September to October 1538

The Phlegraean Fields (Italian: Campi Flegrei [ˈkampi fleˈɡrɛi]; Neapolitan: Campe Flegree, from Greek phlego, "to burn") are a large volcanic area situated to the west of Naples, Italy. It was declared a regional park in 2003. Lying mostly underwater, the area of the caldera consists of 24 craters and volcanic edifices. Hydrothermal activity can be observed at Lucrino, Agnano and the town of Pozzuoli. There are also effusive gaseous manifestations in the Solfatara crater, the mythological home of the Roman god of fire, Vulcan. This area is monitored by the Vesuvius Observatory.

The area also features bradyseismic phenomena, which are most evident at the Macellum of Pozzuoli (misidentified as a temple of Serapis), as geologists puzzled over bands of boreholes left by marine molluscs on marble columns, showing that the level of the site in relation to sea level had varied.

Three geological phases or periods are recognised and distinguished.

The caldera, which now is essentially at ground level, is accessible on foot. It contains many fumaroles, from which steam can be seen issuing, and over 150 pools of boiling mud at last count. Several subsidiary cones and tuff craters lie within the caldera. One of these craters is filled by Lake Avernus.