For this purpose, the town of Dara, [137] fourteen miles from Nisibis, and four days' journey from the Tigris, was peopled and adorned; the hasty works of Anastasius were improved by the perseverance of Justinian; and, without insisting on places less important, the fortifications of Dara may represent the military architecture of the age.

The city was surrounded with two walls, and the interval between them, of fifty paces, afforded a retreat to the cattle of the besieged.
The inner wall was a monument of strength and beauty: it measured sixty feet from the ground, and the height of the towers was one hundred feet; the loopholes, from whence an enemy might be annoyed with missile weapons, were small, but numerous; the soldiers were planted along the rampart, under the shelter of double galleries, and a third platform, spacious and secure, was raised on the summit of the towers.

The exterior wall appears to have been less lofty, but more solid; and each tower was protected by a quadrangular bulwark.

A hard, rocky soil resisted the tools of the miners, and on the south-east, where the ground was more tractable, their approach was retarded by a new work, which advanced in the shape of a half-moon.

The double and treble ditches were filled with a stream of water; and in the management of the river, the most skilful labor was employed to supply the inhabitants, to distress the besiegers, and to prevent the mischiefs of a natural or artificial inundation.