It is a widespread museum that has the crypt of the Duomo as its core, but also involves the other churches of the historic center.

It was conceived and established in 1985, after the earthquake that led to the loss of many churches. Then it was decided to collect artifacts and objects from the Cathedral Treasury and other churches. The exhibition includes valuable evidence from the 17th to the 10th century of painting and sculpture, vestments and goldsmiths.