Housed in the former monastery of San Pietro all'Orto, this museum houses a splendid Maestà (c 1335–37) by Ambrogio Lorenzetti and sculptures by Giovanni Pisano that originally adorned the duomo's facade. The collection of primitive grey alabaster bas-reliefs also came from the duomo, but originally date from an earlier era.
Some local maps feature the museum as Complesso museale di San Pietro all'Orto
