The south façade, known as “Cadena’s door” was completed during the first stages of construction, at the same time as the north façade, and appears clearly asymmetrical because of the great rose-window opened at the top.
The door stands under a round arch with three archivolts above capitals featuring vegetable decoration and harpies. Over the door there are five wonderful sculptures dating to the 13th century, which represent Jesus Christ (in the center) and four apostles: Saint Peter, Saint John, Saint Paul and Saint James.
Above these five sculptures is a frieze with twelve pointed arches which protect twelve gothic sculptures, completed around 1230. The sculptures have been identified as characters of the Old Testament including (from left to right): Abraham, Isaiah, Queen of Saba, King Solomon, Ezekiel, Moses, Melchizedek, Balaam, David, Elias, Saint John the Baptist and Jeremy. Toward the main chapel there are two blind arches superimposed and inside the upper arch is a statue of Virgin and Child.
To the left of “Cadena’s door,” Virgin of Pilar’s Chapel stands out breaking up the original perimeter of the building. The chapel was built between 1748 and 1753 by the Bishop D. Clemente Comenge, a native of Zaragossa.
In the walls of southern and northern naves, which are from the first period of construction, appear a wonderful set of late-Romanesque windows.