Little is left of the original Romanesque character of Cortona's cathedral, rebuilt several times in a less-than-felicitous fashion. Fortunately, its wonderful artworks have been saved and displayed in this museum. Highlights include a moving Crucifixion (1320) by Pietro Lorenzetti and two beautiful works by Fra' Angelico: Annunciation (1436) and Madonna with Child and Saints (1436–37). Room 1 features a remarkable Roman sarcophagus decorated with a frenzied battle scene between Dionysus and the Amazons.