In 2001 the central-southern part of the ex abbey church was excavated. The south and central naves were completely uncovered. The investigation showed that in the medieval period it was a basilica with three naves, characterised by columns made of alternating brick and stone courses. Below the presbytery there was a large crypt which was filled at an early date. The excavation reached the level relating to the church’s use in the 14th century, corresponding with a fragmentary pavement, which at the moment of its obliteration was the object of an unsystematic spoliation. The life of the building was characterised by the continued raising of the floor level, probably due to the continuous problems caused by the rising water-table and the instability of the local hydrographical regime. The floor which ought to correspond to a reorganisation of the building results as being in phase with a masonry structure which is partially conserved in the back of the wall, in which the remains of a semicircular staircase, descending from the entrance threshold down into the church, are visible. A similar staircase was found in 1999 near the building’s entrance in the façade. The church was therefore characterised by an external path which crossed the cemetery area in front of the church; the threshold of the building was reached by several steps and the interior was then reached via another staircase; a further step into the presbytery raised the floor level. This arrangement was obliterated when the floor level was raised. The church was transformed from a basilica with three naves into a single naved one. The floor was made with re-used material from the demolition of part of the building. (MiBAC)