St John’s distinctive Great Gate follows the standard contemporary pattern employed previously at Christ’s College and Queens’ College. The gatehouse is crenelated and adorned with the arms of the foundress Lady Margaret Beaufort. Above these are displayed her ensigns, the Red Rose of Lancaster and Portcullis. The college arms are flanked by curious creatures known as yales, mythical beasts with elephants’ tails, antelopes’ bodies, goats’ heads, and swivelling horns. Above them is a tabernacle containing a socle figure of St John the Evangelist, an Eagle at his feet and symbolic, poisoned chalice in his hands. The fan vaulting above is contemporary with tower, and may have been designed by William Swayne, a master mason of King’s College Chapel.