Paintings include a 7th century painting of Christ on the Cross ( La Croce ) , 14th century works by Pietro Lorenzetti ( Madonna with Child ) and Bartolo di Fredi ( Madonna della Misericordia ) . Paintings include a 12th-century painted crucifix from the Abbey of San Pietro in Vollore , 14th century works by Pietro Lorenzetti ( Madonna with Child ) and Bartolo di Fredi ( Madonna della Misericordia ) .