In 2012 portions of stone material detached from the entrance arch to the Galleria Vittorio Emanuele II. As a result, it became necessary to carry out an emergency manual inspection to identify the parts that were still unsafe. The restoration enhanced the original design of architect Mengoni, with the recovery of the original color scheme and highlighted how, previous maintenance work, had compromised the preservation of the artifact. Case in point, in this regard, are marbles that show a very high degree of disintegration due to poor breathability, partly attributable to previous treatments. These interventions were important because they allowed us to obtain a great deal of new information about the composition and constructional realization of the Arch, which can improve our understanding of the current degradation phenomena and improve its preservation in the future.
The restoration work carried out during the maintenance of the entrance arch from Cathedral Square was many and varied, this was to try to restore the previous cohesion of the materials involved and at the same time avert any new detachments and collapses. During the course of the work, pass-through lesions, already noted by Mengoni, were revealed at two granite lintels. The resulting intervention remedied this situation, eliminating the risk of the stone ashlar falling.