This 13th-century Gothic structure overshadows the other ruins. Entry is through a small porch facing the Hall of the Vicars Choral. The cathedral's western location is formed by the Arch-bishop's Residence , a 15th-century, four-storey castle that had its great hall built over the nave. Soaring above the centre of the cathedral is a huge square tower with a turret on the southwestern corner. Scattered throughout are monuments, panels from 16th-century altar tombs and coats of arms. If you have binoculars, look for the numerous stone heads on capitals and corbels high above the ground.