Upon a rocky height surrounded by precipices was planned an irregular square measuring about 200 feet each way.

Two elongated bastions, one on the north-east and the other on the south-east, guarded respectively the path leading to the gate, and the course of the river.

The covering wall stood thirteen feet high, and closely followed the line of the main wall, except at the north and south corners, where it formed two bastion-like projections.

At Semneh, on the opposite bank, the site was less favourable.

The east side was protected by a belt of cliffs going sheer down to the water's edge; but the three other sides were well- nigh open (fig.