The so-called "cell of San Vincenzo", located along the itinerary that leads to the Grotta dell'Angelo, halfway up the hillside of Mount Raione, was the small monastery detached from the abbey of San Vincenzo al Volturno, probably the seat of the hermit guardian of the " grotto". Mentioned for the first time in a document of 819 issued in Aachen with which the emperor Ludwig I donated the cellam Sanctii Vincentii near the Tusciano river to the Volturnense monastery, starting from the year 1000, with the establishment of the ecclesiastical fief of Olevano becomes independent. Following a rather radical restructuring a few years ago, only the faint traces of the original sacred building remain which can be found in the church with the ribbed vault decorated with stucco, in the service rooms on the ground floor and in the cells of the monks on the high floor. Not only the particular architectural-structural system but even more the highly strategic position of the "cell", on the road that leads to the Grotta dell'Angelo and at the center of the vast plots of land owned by the abbey, lead us to suppose that the small building it also performed a defensive function, precisely because the monks had to guard against frequent external attacks.