The small sacred structure was built outside of Porta di Sant'Angelo, close to the wall of the town of the mondragonese land; its tower was built on the aforementioned wall (where fragments are preserved behind the chapel), where the gap opened in the defensive wall which is still partially visible. The building was probably built on that spot to create a sort of corridor in front of the gate together with the tower that stood on the other side, to ensure greater defence possibilities.
The sacred space used for worship is rather small and the ceiling is covered with a fresco which dates back to the nineteenth century. The central theme proposed by the fresco, brought to light only a few years ago, is the Vergine del Giglio (Virgin of the Lily). At the time, the chapel was closed by a barrel vault with four lunettes on each side, which had circular lights opened on the inside. In the Thirties the crumbling vault was replaced with a ceiling surmounted by a trussed roof. Twenty years later, the wooden stalls occupied by the followers of the brotherhood during the liturgical celebrations and the normal assemblies were also removed.
In this room, similar to the Chapel of the Carmine, the walls are articulated with plaster pilasters with Corinthian capitals. During the restoration of the structure the funeral crypt was also brought to light, whose access is given by a small hatch at the entrance. The hypogeum of the Church, however, was used for the burial of the brothers and their families.