The Chapel of the Holy Crucifix is a quadrangular room topped by a partially preserved pavilion vault.

The arch leading to the chapel, rebuilt in brick, is framed by two pairs of columns decorated with rich vegetal scrolls, in which flowers and anthropomorphic figures alternate.

The columns respectively frame two niches in which two headless stucco statues are still recognizable.

The blocks of the pedestals feature, in bas-relief, allegorical and symbolic decorations: the two outer ones represent the soul subjugated by the devil; the inner blocks, on the other hand, symbolize the purified soul, ready to approach the Eucharist.