 The glorification of Mary in the centre, the incarnation of her son on the left and Old Testament prefigurations and prophecies on the right.One major exception to this scheme is the presence of large statues of St Modesta (a local martyr) and St Potentian on the north west corner of the porch, close to a small doorway where pilgrims visiting the crypt (where their relics were stored) would once have emerged

As well as the main sculptural areas around the portals themselves, the deep porches are filled with other carvings depicting a range of subjects including local saints, Old Testament narratives, naturalistic foliage, fantastical beasts, Labours of the Months and personifications of the 'active and contemplative lives' (the "vita activa" and "vita contemplativa").The personifications of the "vita activa" (directly overhead, just inside the inside of the left hand porch) are of particular interest for their meticulous depictions of the various stages in the preparation of flax – an important cash crop in the area during the Middle Ages.