On each side of the gallery of the museum, installed behind the walled arcades of what was to be a transept of the cathedral, are statues by Giovanni Pisano which once adorned the cathedral façade: prophets, wise men and the sibyl are depicted here with singular power. But the jewel of the museum is the famous Maestà painted by Duccio for the main altar of the cathedral. This exceptional work, commissioned from the artist in 1308, represents the height of his genius.