Maintenance work on the structures and pathways in the Duomo's Archaeological Area, which began in September 2016, has almost been completed. The restoration, entrusted to qualified professionals, was conducted in small sections, thus maintaining visitor access to specific areas. Patinas of a biological nature and salt efflorescence on the floor and walls were removed, followed by the removal of deposits of atmospheric particles. These deposits are not uniform as they are affected by the movement of air and the structural characteristics of the space. In general, all of the surfaces were grey from layers of dust, in some areas so thick that small clumps had formed.
The restoration of the baptistery is part of a larger restoration project known as "Sotto Duomo" [Under the Duomo] which will include work on the unfinished underground spaces that are to be cleared of the equipment and materials currently encumbering them and then renovated.