This museum unites many objects from the neighbouring Chiusi necropolises: sarcophaguses, cippi and funerary urns, as well as sculptures, Canopuses (Egyptian human-headed vases), commemorative plaques made of clay, vases, lamps, and jewellery epitomi..

This Cathedral was rebuilt in the 12C over the ruins of an early-Christian basilica from the 6C. Its three naves are separated by 18 ancient columns that were derived from various roman buildings.

In addition to the Etruscan-Roman and early-Christian relics found under and around the Cathedral, this museum accommodates a lovely collection of illuminated religious books from the 15 and 16C, which came from the Abbey of Monte Oliveto Maggiore..