The town, founded, with the castle, by King Edward, is somewhat of a parallelogram in plan. It is contained within a curtain wall, strengthened by ten towers, of which two form the east and west gatehouses, and three cap the principal angles of the enclosure. They are either cylindrical or half cylinders, open at the rear.
The south end of the area is closed by the castle, of which the principal face is thus towards and within the town. The opposite or southern face rests upon the Seiont, as does the western, and did, to some extent, the eastern end. Wilson’s picture, taken in the last century, shows the walls rising almost from the water’s edge, and the cross ditch before the Queen’s Gate still open, but at this time a broad quay intervenes between the castle walls and the river, and of the broad and deep ditch separating the fortress from the town only a part remains. The ditch was, probably, deep enough to admit the tidal waters.
The castle somewhat resembles an hourglass in plan, its outline being governed by the rocky ridge on which it stands, and which lifts it a few feet above the level of the town. It is in length about 100 yards, and in breadth from 30 to 40 yards, the narrowest part being at the centre. Its outline is polygonal, and on each angle is a tower, also polygonal. Of these there are nine, two of which are double, and form gatehouses. There are also two smaller towers, also polygonal, in the centre of two of the curtains. The ground falls rather steeply from the south-east end, but at its lowest is some feet above the water level.
The main or King’s Gatehouse, a very noble structure, is in the centre of the town front, and occupies a re-entering angle of the wall. It is broad and high, with an unusually lofty and ornate archway, in the upper part of which is a statue of Edward II., who completed the castle, and below this the recessed gateway. Two bold half-octagons flank the entrance, the approach to which was by a drawbridge, now superseded by a work in masonry. The portal is broad and high, vaulted and ribbed, with the usual portcullis grooves, rebates, and bar holes for doors, and meurtrières in the vault. On either side is a lodge, an unusually spacious chamber. Both of the flanking towers are looped, and in that to the right is a mural gallery, with loops completing the command of the approach. The rear of this right-hand tower is prolonged into a square building forming the prison tower, in one angle of which is a well staircase leading to the upper floor of the gatehouse and its roof. At the foot of this staircase a small portcullised doorway opens westwards upon the kitchen.
From the Prison Tower a narrow building connected the gatehouse with the opposite or Exchequer Tower, and thus divided the castle into an eastern or upper, and a western or lower, ward. A handsome archway pierced this building, and opened from one ward to the other. Building and gatehouse are gone, but the jambs of one side, with two portcullis grooves, show that the portal was strong and was ornate.
Besides the King’s Gate the upper ward was entered by a second or Queen’s Gate, a very remarkable structure, seeing that it is placed at the highest part of the fortress, and that the cill of its entrance is some 25 feet above the present ground, and must have been 12 feet or 14 feet more above the bottom of the now filled-up ditch. How this entrance was approached does not appear, if by a drawbridge the pier on which it fell must have been a very lofty structure, and a sort of viaduct must have led up to it. The portal is vaulted and ribbed, and had a portcullis and gates, but the lateral chambers do not open from it. The rear of the gatehouse seems not to have been completed, but close to it, to the west, is the jamb of a small portcullised gateway, with ornate mouldings. Into what it led is not very apparent.
The towers, though differing widely in details, are all of one general type, and probably designed by one hand. Each has a basement at about the exterior ground level, damp and dark, and only to be reached by a ladder from the floor above. Possibly these basements were not intended to be used. They were not vaulted, and have no sewers. Each tower has a first floor at the court level, and at this level, or a few steps above it, the wall is pierced all round by a mural gallery, looped to the field and connected with divers mural chambers and garderobes. The second floor has windows of a larger opening, as has the third or uppermost. Each floor has a fireplace, usually a mere opening in the wall, and each is reached by a well staircase, which begins at the first-floor level and ends in a tall turret which rises some 20 feet above the roof. From the upper floor a doorway opens out upon the rampart of the curtain. The floor was all of timber. The roof was almost flat, having a very slight pitch to a central ridge, and was covered with lead.
The curtain, everywhere unusually thick and lofty, along the north side was looped in two stages, showing that it gave support to long ranges of buildings, probably barracks, with thick walls and very low-pitched lead-covered roofs. These buildings are wanting, but the towers and curtains are toothed, to give bond to their walls when built.
The most remarkable part of the castle is the arrangement for the defence of the southern or river front. On this face the curtain is of immense thickness, extending from the Queen’s Gate to the Eagle Tower, and including in that distance the Prince’s and the Exchequer Towers, and two others of smaller dimensions. This wall, from the Queen’s Gate to the Prince’s Tower, contains, at a little above the court level, a broad and lofty gallery, which not only pierces the curtain, but is continued through the walls of the towers, with an occasional vaulted chamber or lobby, as a “place d’armes.” This gallery is looped towards the field, and has an occasional window and door towards the court. It descends by steps so as to preserve its level as regards the court, and in its walls are several garderobes.
Above this, of the same length and similarly constructed, is a second gallery, also looped towards the field, but either the inner wall and roof of this gallery have been removed, or, more probably, never completed, for it now remains as an open platform. The thicker and outer wall, however, is perfect, and carries what is still a broad rampart walk, or allure, reached by occasional flights of steps in the wall from the upper gallery. Thus was provided a triple line of loops, and these loops are not, as was often the case, mere air-holes, but are so contrived as to afford ample scope for the effective use of either longbow or arblast. No body of assailants, however brave, unprotected by armour or unsupplied with regular siege appliances, could have withstood such a line of defence, manned, as it would be, with the first archers in Europe, exposing those without, in front and flank, to a shower of clothyard shafts and iron-pointed quarrells.