In the south transept, the lancet and oculus windows in the two large bays on the east, built in 1220–1227, are modelled after those in the lower choir of Chartres Cathedral. A pointed arch, a tribune for singers, and a balustrade were added in the 15th century. A sculpture of a head, wearing the hat of an architect or magistrate, gazes from the balustrade at the pillar of angels. Under the balustrade is a large painting on wood illustrating the Nativity, in a sweeping landscape. It also dates from the 15th century.