An isolated tower away to the left is one of the most ancient portions of the castle. It is known as 'Mortimer's Tower,' from a tradition that Hugh de Mortimer was imprisoned within its walls towards the close of the twelfth century. But that is another story, whereof more anon. Let us now pass on to the inner ward, which is surrounded by tall, irregular structures, whose crumbling walls and battlements have been brought to a rare state of soft, harmonious colouring, by the mellowing touch of time. Out in the courtyard, detached from all its neighbours, rises a small circular twelfth-century chapel, whose beautifully enriched, semi-headed west doorway and curiously carved string-course, bespeak the Normans' handiwork. This chapel is almost unique of its kind in England. The fine chancel arch still remains, but of the chancel itself only the foundations can now be traced. In former days the chapel was hung with 'Armes in colours, sitch as fewe can shewe,' 'So bravely wroughte, so fayre and finely fram'd, That to the Worlde's end their beauty may endure!' We now pass out again into the green courtyard. Turning our backs upon the entrance way we see before us an extensive group of buildings, now roofless and half in ruin, yet stately in their decay. In the centre, approached by a sort of sloping gangway, rises a noble hall, a spot famed in local history as the scene of the earliest performance of Milton's 'Masque of Comus.' One of the adjacent chambers is pointed out as that occupied by Prince Arthur, son of Henry VII. Beside the Keep-tower are the scanty ruins of the castle kitchen, which, to judge from the fireplace, an enormous oven, and some rusty iron utensils of proportionate size, must have been on a scale commensurate even with the needs of this vast mediæval ménage. Close at hand is the castle well, which, though not enclosed within the area of the Norman keep, is not far away from it, and was probably protected by its adjacent outworks. Down in the basement of the keep is a dark, vaulted chamber, far below the surface of the ground. This was originally used as the castle chapel, whereof two well-proportioned Norman arches still remain, supported upon slender pillars with simply ornamented capitals. A curious arrangement of walls and passages here has given rise to an obscure myth concerning lions, or other wild beasts, having been kept in this chamber to devour obnoxious prisoners, when it was used at one time as a dungeon.