The portal of the south transept contains four archivolts astonishingly rich in decoration. These sculpted half-arches do not present a unified narrative, as do tympana portraying the life of Mary, the Last Judgment or parables. Rather, they evoque, from outside to center, the bestial world, the hereafter, and the world of the saints, before embellishing the doorway to the sanctuary with graceful animal shapes recalling the marginal illuminations in manuscripts.

Certain mythological creatures or literary allusions are recognizable in the upper archivolt (see detail). On the whole, however, it is instructive to see in the entire arch a general opposition between the world of sinfulness and the world, portrayed below it, of the saints and of paradise. This portal then becomes an echo of the struggle between the vices and virtures depicted on the central portal of the west facade.