In the opposite direction the parapets alone spring, as two arches, from the pier to the gateway, and serve to steady the pier, but the roadway is omitted, and its place supplied by a drawbridge. This arrangement is not uncommon, but is here specially necessary, owing to the height and consequent weakness of the pier. Upon the counterscarp of the ditch is a _tête-de-pont_, from which a steep road descends by a traverse towards the town. This gate, though open, is but little used. The ordinary gate is modern, and near the site of Canon’s Gate. The Constable’s Gate is of the Decorated period. Its interior is said to be very curious, but is not shown. Sixteen towers, including Clopton, Godsfoe, Magminot (4), and Crevequer’s Towers (2), protect the north-west face. Clopton is a hexagon; the name of Magminot is borne by four towers. The two towers bearing the name of Crevequer mark the position of the great postern, a very curious work. Passing from the north gate of the inner ward, a range of arches cross the ditch and the outer ward, and terminate abruptly in a large low pier with salient angles to the right and left. Opposite to the pier, and no doubt at one time connected with it by a drawbridge, rise a pair of circular towers (Crevequer), connected by a heavy curtain and flanked by lesser towers (Magminot) at short distances, all forming part of the _enceinte_ of the outer ward. Towards the field the curtain has a salient angle, and from its base a covered gallery descends into the outer ditch, and there reaches St. John’s, a drum tower built in the middle of it. The gallery passes through the first story of the tower, and terminates in the counterscarp, in a circular chamber cut in the chalk, and from this chamber three tunnels radiate to different parts of the glacis, of which one formerly led to a distant postern, and another still communicates with the old spur-work, attributed to Hubert de Burgh, and converted into a modern ravelin. Two other tunnels, apparently of Edwardian date, leave the main gallery under the castle wall, and the basement floor of St. John’s contains two sally ports, opening into the bottom of the ditch. The modern access to these galleries is by a shaft sunk in the pier of the old drawbridge, but the old entrance was nearer the curtain. The French siege of 1216 was directed upon this quarter. The approaches were made from the west below the Constable’s Gate, and under cover of a trench and breastwork. While the attack was impending Sir Stephen de Pencester brought a reinforcement into the castle by the postern under Godwin’s Tower. De Burgh, taught by experience, threw up the advanced work which still, under a changed form, covers the northern end of the castle, and it was to reach this in safety that the gallery from St. John’s Tower was executed.