Pozzo del Diavolo: was this cave created by Hercules’s wrath, the devil, or volcanic activity?

We are in Italy, in Lazio region, above Vico Lake in the beautiful beech forest of Monte Venere, part of the UNESCO’s Primeval Beech Forests of Europe transnational network of protected sites. At 507 meters above sea level, Lake Vico is the highest volcanic lake in Italy and the beech forest of Monte Venere is among the lowest in the country (most beech forests are located above 900 meters).
Thanks to its peculiar natural characteristics, the lake offers a rich variety of plant species and different environments, allowing the life of many animal species. Along the shores of the lake, from February to the end of summer, you can see a diversity of wild orchids that further enrich the territory.

A short distance from the village of Caprarola, we can admire the so-called Pozzo del Diavolo, or Devil’s Well, is the only known volcanic cave in Lazio region.
It is about 10 meters deep and 40 meters long, and the entrance is about five meters wide.
The sloping floor of the cave is littered with volcanic rocks that presumably collapsed from the entrance and from the ceiling. It seems that the lake filled up a caldera that formed almost 140,000 years ago, after intense volcanic activity shaped the landscape of the Cimini Mountains. Monte Venere was originally an island, before the Etruscans drained the lake to create new agricultural land.
In fact, remains of pottery from the 5th and 4th centuries B.C. were found inside the cave and are currently exhibited at the local museums in Rome (Pigorini) and Valentano.

However, according to a very ancient legend, the cave is the result of Hercules’ fury: the legendary hero smashed his club in the earth, forming the cave, from which water sprang and formed the Lake of Vico.
As story goes, Hercules, as a sign of challenge towards the local populations, strongly pushed his club into the ground where the Devil’s Well now stands. Nobody could extract the club, until the hero himself, extracting it, created a huge flow of water from the ground that filled the valley below, generating the current lake.
This scene is represented in a late 16th century fresco by Federico Zuccari in nearby Palazzo Farnese in Caprarola. This scene should represent the difficulties that Alessandro Farnese had to face for the construction of a new aqueduct, for the lowering of the lake level and other interventions aimed at improving the territory.
Only a mystery remains.
Why does the cave have such a sinister name?
It is unclear what the devil has to do with all this. However, like many other places in Italy, it seems like anything that could not be explained would be simply the devil’s work….

Author’s note: an about 40-minute trail leads from the picnic area near Fontana Canale to the entrance of the cave.