The authors of _Ocheïdir_ have pointed out that the original scheme of the castle did not include the present north door, nor yet the massive enclosing wall with its towers and gates. As it was first planned, the north door stood well within the existing entrance, between two segments of towers. A part of these towers is visible in rooms 2 and 3. But when the walls had been raised about 2·80 metres from the ground, the plan was altered and the outer wall and north door added to it. The north palace wall, with its round towers and gateway, was then incorporated in the larger outer wall. A glance at Dr. Reuther’s plan will show how this was effected (Fig. 1). Although the alteration took place while building was in progress and does not denote a later period of construction, it is yet of importance, as I shall have occasion to show later. On the first floor the gate-tower is occupied by three vaulted chambers, 88, 89, and 90. The central room, 88, is 4·50 metres wide and therefore wider by 1·50 metres than the passage room, 1, below it. Consequently the slits between the transverse arches of 1 do not take up the whole width of 88, but leave a passage along the wall on either side. The chamber is low, measuring only 3·55 metres to the top of the vault. The vault oversails the wall; the lower part is composed of stones laid horizontally, the upper part of stones laid in vertical rings, with an inclination backwards against the north wall. At the southern end a space between the vertical rings and the south wall is filled in with horizontal courses (Plate 12, Fig. 2). The arches of the side doors break into the vault. In the north wall there is a large window, the upper part of which has fallen away, though some of the lower part remains. It is slightly recessed on the exterior (Plate 11, Fig. 2), and Dr. Reuther gives the explanation of this recess. It contained the groove of the portcullis, which has been obliterated below owing to the rebuilding of the north door at a later period. In the south wall of room 88 there are three arched windows opening into the great hall. The central window is the largest; in all three the arch is surmounted by a shallow arched niche. The narrow vaulted rooms 89 and 90 are approached by round-arched doorways and lighted only by very small windows high up in the north wall. In room 89 there is a staircase leading up to the second floor. Rooms 89 and 90 open into long corridors corresponding in width with the corridors 5 and 6. [Illustration: FIG. 1. North wall of palace, showing original scheme. (From _Ocheïdir_, by kind permission of Dr. Reuther.)] [Illustration: FIG. 2. Arch construction. (From _Ocheïdir_, by kind permission of Dr. Reuther.)]