The ancients identified it as one of the theaters of the Gigantomachie between the gods of Olympus and the giant sons of Gaea. In that ardent "phlegraean" land, the elements manifested themselves at their maximum destructive and creative force, alternating with periods of sudden restlessness as many phases of harmony and beauty lavish of gifts for men.
Thus, the Phlegraean Fields, the only active super volcano in Europe, have become the land of myth, celebrated by poets and artists of all ages since ancient times. Fascinating and inspiring destination, between the eighteenth and nineteenth centuries, for generations of young European travelers, who went there to explore on the back of a mule among ancient craters, active fumaroles, thermal waters, Greek and Roman remains, lush woods and fertile soils , producers of excellent fruit.
About forty volcanoes and an unknown number of minor volcanic buildings. An enormous quiescent caldera about fifteen kilometers in diameter, which extends from Monte di Procida in the north to the Camaldoli and Posillipo hills in the south, encompassing gulfs, inlets and lakes. All shaped by the elements in the course of a complex geological history that began over 40 thousand years ago, in which science identifies three different main phases.
The First Phlegraean Period covers the time span between 42,000 and 35,000 years ago. It was 39,000 years ago that the eruption of the so-called Campanian gray tuff took place, to which the volcanologist Rittman linked the birth of the Archiflegreo, a gigantic volcano that spread ignimbrite throughout much of Campania. It was then that the Camaldoli hill, the northern and western ridge of Monte di Cuma and the coastal walls of Monte di Procida were formed.
The Second Phlegrean Period lasted for over 25,000 years, precisely from 35,000 to 10500 years ago and was marked, about 15,000 years ago, by the great so-called eruption of yellow Campanian tuff, caused by a large underwater volcano. Yellow tuff, used as a building material since Greek times, is present in the hills of Posillipo and Camaldoli, in the north ridge of Quarto, in the mountains of San Severino and Licola, on Monte di Cuma and Monte di Procida. Inside the crater rises Monte Gauro.
The Third Phlegraean Period, which began about 8000 years ago, lasted until the last eruption of 1538. In this phase almost all the Phlegraean volcanoes were formed within the great caldera of the Second Period. It is the white pozzolan that characterizes the volcanic areas of Bacoli, Baia, Pozzuoli, Agnano, Montagna Spaccata, Lake Averno and Monte Nuovo, the result of the latest eruption after more than three thousand years of Quiescence. Lake Averno is the only one of volcanic origin in the Phlegraean Fields, while the other three, all coastal - Lucrino, Fusaro and Miseno - were formed by barrage.
In addition to fumaroles, gaseous emissions and thermal mineral springs, typical phenomena of secondary volcanism, Campi Flegrei is periodically subject to ascending bradyseism, when the soil rises under the pressure of underground magma, or descending, when the soil tends to lower . In the city of Pozzuoli, where the so-called temple of Serapis demonstrates the historicity of the phenomenon, between 1970/72 there was a rise in the port area of 170 centimeters; ten years later, between 1982/84, the quays rose by three meters, then from 1984 the descending phase began, which lasted until 2005. Subsequently, the ground slowly began to rise again.
