Most of the Assyrian architects did likewise. See for example the plan of Sargon's city, Dour-Saryoukin (Fig. 144). Its circumvallation incloses an almost exact square, the diagonals of which point to the north, south, east and west respectively.[399] In the large scale plans that we shall give farther on of the palace and of some of its parts it will be seen that the parallelograms of which that building was composed also had their angles turned to the four cardinal points. It was the same with the structures sprinkled over the summit of the vast mound of Kouyundjik, in the centre of what once was Nineveh. [Illustration: FIG. 145.--General plan of the remains at Nimroud; from Layard. 1, 2, 3 Trenches, 4 Central palace, 5 Tombs, 6 South-eastern edifice, 7 South-western palace, 8 North-western palace, 9 High pyramidal mound.] On the other hand in those ruins at Nimroud that have been identified with the ancient Calah, it is the sides of the mound and of the buildings upon it that face the four cardinal points (Fig. 145). The plan given by Layard of the square staged tower disengaged in his last digging campaign at the north-western angle of the mound shows this more clearly.[400] Nearly half the northern side is occupied by the salient circular mass that is such a conspicuous object to one looking at the mound from the plain. We do not know what caused this deviation from the traditional custom; a reason should perhaps be sought in the configuration of the ground, and in the course here followed by the river which then bathed the foot of the artificial hill upon which stood the royal dwellings of the Tiglath-Pilesers and Assurnazirpals. The first of these two methods of orientation had the advantage of establishing a more exact and well defined relation between the disposition of the building and those celestial points to which a peculiar importance was attached. It must also be remembered that such an arrangement gave a more agreeable dwelling than the other. No facade being turned directly to the north there was none entirely deprived of sunlight, while at the same time there was none that faced due south. The sun as it ran its daily course would light for a time each face in turn.