It’s a cleft cavity between the rocks on the slopes of the Morge Mountains, that ever since antiquity has sparked the interest and imagination of historians and scholars.
Believed by some to a be a deep natural crater formed in the karstic territory, others have claimed that it is the work of man, without however establishing for what purpose it was excavated.
Plinius, who described the Aquae Marciae, believed that this spring, which originates from the Peligni Mountains, actually fed into the cavity after crossing the territories of the Marsi, the Fucino, and the Frigida valley, and then descended towards Rome.
On the other hand Sextus Julius Frontinus tells us that this ancient water sprouted from different springs and in particular in the areas of Arsoli and Riofreddo.
The humanist and historian Biondo da Forlì (1392 – 1463) informs us that “throwing a stone weighing two pounds into it, it did not reach the bottom until after having recited with the due pauses two of Virgil’s hexameters”.
Recent explorations have managed to establish that the well, with its 3 metres of diameter at the surface, drops about 50 metres vertically, and then continues as a tunnel, thus lending credence to the hypothesis that it is karstic in origin, as the nature of the land would have suggested.
In the 16th C. the prison for capital crimes was established here, and some have identified it as the well’s tunnel which it is believed rises up to the height of what is now Via dell’Olivo.
Nowadays the opening of the well is closed by a heavy grille; visitors throw small stones down into to try and fathom its depth.