The Neapolitan-phlegraean territory consists of yellow and grey tuffaceous soils produced by a volcanic system giving this area its geo-morphological characteristics .
There are numerous recognizable craters in the Phlegraean Fields area bordered on the east by the Gulf of Naples and on the west by Literno. Among the largest ones we include: the Gulf of Baia, the harbor of Miseno, the Torregaveta crater, the crater of Chiaia, Pozzo Vecchio (Old Pit) and Torre Murata in Procida, the islet of Vivara and Mount Epomeo in Ischia .
Characteristic of the Phlegraean area is the bradyseism .
With the term bradyseism we mean the raising and lowering of the soil compared to the sea level, due to the variation of the pressure exerted by the internal heat sources of the earth, on the pyroclastic mass.
This phenomenon since ancient times fueled numerous myths related to the idea of afterlife world.
The warm waters arising from the subsoil have been repeatedly connceted with Pyriphlegethon and Cocytus, the rivers of the kingdom of the dead.
Lucrino was identified as an Acherontean swamp .
Still in Lucrino it was imagined the Giants were buried after being defeated by the Gods of Olympus, and in their attempts to escape, they shaked up the earth.
Another myth would have as protagonist the island of Ischia, whose first inhabitants were the Cimmerians, who would live in underground homes without ever seeing the sunlight.
They would make their living by extracting metals from the caves .
On these same lands would live the Lestrigoni, huge and vicious creatures that would have hurled boulders against the ships of Ulysses.
Leaving aside the mythical elements, the first human settlements in the Phlegraen area are very recent, as the documentation from Paleolithic and Mesolithic in all probability were destroyed as a result of volcanic eruptions, and bradyseism .
The first records are from Neolithic age and consist of fragments of arrowheads and pottery shards .
From Eneolithic we have a greater amount of evidence :
At Materdei, in Naples, following the discovery of two tombs, copper daggers were discovered, while in Ischia and on the islet of Vivara fragments of Mycenaean pottery were found.
From the Iron Age, there are instead traces especially in the area of Cuma, where traces were found of a native settlement built on the rock giving the possibility to visually check anyone entering the Gulf of Naples