The hypogeum, that is the underground construction studied and surveyed by archaeologists Dr. Brogi Francesco and
Dr. Rubegni Elisa, has the structure of a "waste pit" with vertical walls: this type of
underground cavity was already found in the medieval period and each house had its own to
discard bones and inorganic solid waste.
In the graffiti found inside the "waste pit",a human face and two letters B that probably recall the name of the same place (Barottoli)can clearly be seen; there are also some "signs", which are however of difficult interpretation, such as wavy lines. These graffiti date back at least to the 20th century, which seems plausible, as both the B letters inside the "waste pit" have a fairly modern - but certainly not current- structure.