The rebuilding of Modena cathedral in 1099 is a key landmark in medieval history for many reasons, of which two are of most importance. IntegrityOver time, Modena’s monumental complex has retained its historical, social and artistic features that define its Outstanding Universal Value. The complex has survived relatively intact with the cathedral, tower and buildings with a traditional relationship to the church around the Piazza Grande. AuthenticityThe nominated monumental complex is undeniably authentic as far as its design, form, materials, and function are concerned. From the point of view of restoration and preservation, Modena cathedral represents an exemplary case, showing as it does a century-long history of interventions and initiatives, warranting a chapter of importance in the history of Italian heritage conservation.