Museo dell’Opera del Duomo is situated in the right aisle of the Duomo and keeps pieces of art that were originally in the cathedral. The ground floor large room preserves twelve Gothic statues by Giovanni Pisano that bedecked the duomo’s lower façade. The ground floor also houses the Renaissance marble lunette Madonna con Bambino which is thought to be Donatello’s, bas reliefs made between the 13th and 15th century, a frontage of a Roman sarcophagus and a Madonna con Bambino by Diotisalvi de Speme. A first floor room is devoted to the Maestà by Duccio di Buoninsegna (Picture 1, 2 and 3). This late medieval great work of art is considered one of the most important pieces of art of the period.