The 12th-century south portal. It has no tympanum, but the four archivolts are alive with sculpture. From a distance the sculpture forms a repetitive pattern, providing a pleasing visual rhythm. But closer inspection reveals that the pattern is actually a procession of fascinating figures - human, animal, and somewhere in between.
The first (inner) archivolt is decorated with a bas-relief of six animals among vines. The second archivolt has 24 sculpted figures with halos, holding books and containers and facing sideways; presumably these are the 12 apostles and 12 prophets. The third archivolt has 31 front-facing figures with crowns, vials, and musical instruments, identifying them as the 24 Elders of the Apocalypse (aesthetic and architectural factors required the increase in their number). These two middle archivolts are supported by atlantes figures underneath, which can only be seen from below, standing in the doorway.
The outer archivolt is the most interesting of all, populated with larger figures of beasts and hybrid creatures. Most derive from the medieval Bestiary, in which real and mythical animals were given symbolic meanings. Among the parade of characters is a siren, a sphinx, a large owl and a donkey playing a harp. The figures generally face away from the center and each one is carved on a separate stone block that supports the arch.