Coastal cave on the southern side of the promontory, reachable on foot along the same hiking route that leads to the Grotta delle Capre and the Grotta dell’Impiso, in the area known as Quarto Caldo. Like the nearby caves, it has yielded evidence of prehistoric occupation over time, helping, together with the Guattari Cave and the Grotta delle Capre, to make the Circeo promontory one of the world’s key sites for studying Neanderthal man and his traces in southern Lazio.
The Fossellone Cave, reached from the Historic Centre via the Via del Faro, lies about 200 metres west of the Grotta delle Capre and takes its name from its wide circular opening, caused by the collapse of the vault, which has created a very evocative sinkhole-like space that can be visited from land and sea. The first investigations were carried out by Alberto Carlo Blanc, and the cave’s stratigraphy immediately proved very interesting for the large number of stone tools and fossils found. After an interruption caused by the Second World War, excavations resumed in 1947, concentrating on the upper levels (1 to 11). Later they also reached the lower levels (11 to 51), down to the deepest layer of the ancient surface, a Tyrrhenian marine beach deposited during the last Interglacial (about 130,000-120,000 years ago). Above a layer rich in Tyrrhenian molluscs lies a thick continental deposit with an archaeological sequence ranging from the Middle Palaeolithic (the age of Neanderthal man) to the end of the Upper Palaeolithic (the age of Homo sapiens). The cave fill consists of 51 layers, 14 metres thick in all. Of these, the first ten show no human traces, which were found between layers 41 and 23, with Mousterian stone tools made by Neanderthal man. After an intermediate layer of sterile clay, no. 22, marking the visible transition from the age of Neanderthal man to that of Homo sapiens, layer 21 contains Aurignacian tools. Aurignacian is the name given to the stone-tool culture of the first Sapiens to arrive in Europe. The tools found in the Fossellone Cave were made from small flint pebbles using a technique found only in the Circeo area. These local features led Blanc to propose the name “Circeian” for this Aurignacian pebble culture exclusive to the Pontine area.
