Artaxerxes built an Apadana against the west front, of which the foundations, as well as enamelled bricks and fragments of marble pillars and inscriptions, have been found (_f_ 25 in plan). (Cf. p. 127 _et seq._) [Illustration: FIG. 44.—Complete plan of Southern Citadel. N. Ninmach Temple. I. Ishtar Door. ] XI THE EAST FRONT OF THE SOUTHERN CITADEL The east front consists of a defensive wall that ran parallel with the Procession Street (cf. Fig. 44). It is guarded by cavalier towers placed at short intervals, and the principal entrance is a doorway inserted in a shallow recess and flanked as usual by two towers. The recess is shallower on the north than on the south side. The wall itself does not run exactly north to south, which is the direction of the greater part of the palace, and care has evidently been taken to render this deviation as little noticeable as possible. This doorway is perhaps that of Beltis (_Steinplatten_ inscription, col. 5, 17). [Illustration: FIG. 45.—Arched doorway in Southern Citadel. ] To the south near this gateway is an older piece of wall which in many respects is different from the rest. The bricks are smaller (31.5 × 31.5 × 7.5), the joints are formed of asphalt and reeds, the asphalt is laid flush with the face of the wall and has oozed out over it, giving it a blackish appearance, in marked contrast with the neighbouring wall of Nebuchadnezzar’s time, which is lighter in colour, as the asphalt does not show on the surface. This piece of wall contains an arched gateway (Fig. 45), with a threshold that lies about 6 metres below the street pavement. This gate, which is generally known as the arched doorway, was blocked up with mud bricks during the general raising of the ground. It seems, however, that during a later period a door of secondary importance was placed here, of which a small part of the frame still exists. It must have led into the palace that lay behind it. It had two doors, one directly behind the other, as we may infer from the rebates that project by one brick both on the inner and outer sides of the wall. The inner door could only be opened by any one who wished to enter after he had entered the small chamber and had closed the outer door behind him. The outer door could be fastened by a large wooden bolt which pushed backwards and forwards in a cavity in the northern wall.