The origins of the cathedral are from the first centuries of the Christian time. Its particular placement coincides with the original site. The church was built out of the medieval city walls, probably because a secure natural place like Colle San Leonardo was needed at the time.

Works carried out

• encircling of stone piles with fabric stripes;
• consolidation of the arches, vaults and stone piles with resin injection;
• cleaning of the stone surface of arches and piles.