Karst cave on the Circeo promontory, part of the rich complex of about forty caves, mostly of karst origin, that open along the coast and inside Mount Circeo. Like many of the promontory’s smaller caves, it is not among the best known to the general public, but together with the other cavities it helps make this area one of the densest and most interesting coastal cave systems in Lazio.
Over time the shoreline here has shifted considerably, as a result of the climatic fluctuations that have marked the history of the planet (the Quaternary era). The depth of the gulf’s waters therefore also changed: shallower in warm periods, actually dry land in cold periods, and somewhere in between during interglacial ages. These climatic swings brought radical changes in the plants and animals living here and shaped the landforms we recognise today in the coastline, rich in caves, in the finds unearthed inside these natural chambers and on the seabed. The road to the Lighthouse, Provincial Road 90, leads to the area called Quarto Caldo. A short parallel road nearer the sea runs from Torre Fico to Provincial Road 90, and it is along this route that you come to the cave, small in size but of great interest. It lies about 40 m above sea level and was discovered by the surveyor Andrea D’Andrassi, municipal technician from 1940 to 1960, during works on the road now called Via Grotta delle Capre. Visited by Professor Alberto Carlo Blanc and other figures of the time, it was described as a find of considerable historical and scientific interest, as inside it marine beach formations can be seen at a height of about 34 m. A thick stalagmite seals the base, made of a marine sediment probably older than the Eutyrrhenian. Located just above the Grotta delle Capre, its entrance is half hidden by vegetation: Mauritanian grass (Ampelodesmos mauritanicus), tree spurge (Euphorbia dendroides) and other garrigue shrubs. On the inner walls you can see holes bored by lithophagous molluscs, better known as date mussels, which lived on these coasts washed by the Tyrrhenian Sea during the Riss-Würm interglacial (about 100,000 years ago!).