Advocated from the early Corrado Ricci this century, was established thanks to the Canon of the Cathedral Maurice Carr. Damaged in 1944, was completely cleared up and reopened to the public by the Superintendent in 1956. Closed in the 1980s for structural interventions and to provide it with alarm systems and fire protection was finally reopened on December 19, 1992. The Museum aims to be the evolution of the memory aspect of the Cathedral over the centuries through architectural artifacts, artwork and liturgical objects. Also testimony of Christian origins and history in devotion and unity in the liturgy of the whole Diocese volterrana.