This was the fourth campaign of excavations carried out by the School of Specialisation in Architectural and Landscape Heritage, Rome La Sapienza University, with the participation of the Pontificia Università Gregoriana University of Rome, the Natural History Museum of Hungary and
Eötvös Loránd University of Budapest.

The 2017 excavations took place in the final part of the courtyard that extended in front of the church and is closed by the present terrace wall to the west and to the south by the facade of several rooms now used by the religious community that resides in the complex. Once the layer of soil forming the courtyard surface was removed, traces of several structures relating to modern phases in the area were exposed. They were constituted by mortar surfaces, patches of brick and stone floors, a pit, perhaps for planting, a small dry-stone wall and the remains of a brick-built drain. The foundations of the walls now forming the south front of the courtyard were also identified and which, like the standing walls, date to the medieval period (13th-14th century), and a uniform surface of stones and weak mortar that extended for about 6 m across the entire excavation area was also exposed.

This layer corresponded with the levelling of the extrados of a masonry-built barrel vault that was part of an underground chamber accessible from the abbey’s lower courtyard and now used to house a water tank. The room was built in the medieval period as shown by the construction of the perimeter walls and was constructed to create a terrace and increase the usable area of the surface above it. In this way, the link between the monastery’s lower courtyard and the upper church was guaranteed, perhaps via a ramp or steps. A brief section of one of the two longitudinal walls belonging to another underground room to the north-east of the other was identified. On its west face, there were traces of the spring lines of two transversal brick arches that were demolished during the late 18th century, when these structures were definitively buried.