Of each of the two gateways two widely projecting towers close to the entrance are still standing (Fig. 19), and behind them a space closed by a second door. This space, which is generally called the gateway court, although it was probably roofed in, shows clear signs that its primary object was to protect the leaves of the double door which opened back into it from the weather, and also that it strengthened the possibilities of the defences. In the case of smaller gates which do not possess these interior chambers, the leaves of the doors were inserted in the thickness of the wall, which afforded a protection; an embrasure which is absent in the gateways. On the northern gate the gateway chamber lies transversely, on the southern it extends along the central axis. Here also it is enclosed with walls of such colossal thickness that it may be supposed to have supported a central tower of great height, but nothing remains in proof of this. This assumption is delineated in Fig. 21, while in Fig. 43 it is taken for granted that the gateway chamber was commanded by the towers. Here, as in all the other buildings, we have little to guide us as to the superstructure. Among the ornaments in a grave in the Southern Citadel was a rectangular gold plate (Fig. 20) which on the face represents a great gateway. On it, near the arched door, we see the two towers overtopping the walls, while on their projecting upper part triangular battlements and small circular loopholes can be seen. Of the latter we found thick wedge-shaped stones under the blue enamelled bricks, and also part of the stepped battlements in blue enamel which, on the whole, may have had an appearance of triangles. [Illustration: FIG. 21.—Section through the Ishtar Gate. ] [Illustration: FIG. 22.—Grooved expansion joints at the Ishtar Gate. ]