The “old wall,” as it is called by Josephus, first erected by David and Solomon, and strengthened by succeeding kings, commences at the tower of Hippicus, and had its course on the west and south, directly along the edge of the valley of Hinnom. On reaching the valley of Kedron, it bent to the northward, and curving again to the east just below the pool of Siloam, joined the temple wall nearly at its south-eastern angle. On the northern side, starting again at the tower of Hippicus, it kept along the edge of the bank above the valley of Cheesemongers, until curving opposite the Xistus, it here crossed the valley, and passing by the Xistus and the council-house, joined soon after the western wall of the temple, probably at the south-western angle.[36] He does not tell us what is meant by “the Xistus,” but it is probably from the Greek word _Χιστος_, “a division” or “separation;” and I suppose refers to the branching of the valley of the Cheesemongers, one part keeping along by Mount Zion, and the other just on the west of Mount Moriah; the latter branch, as I have already said, was filled up by the Maccabees. Just south of the temple, on the ground sloping down to the pool of Siloam, was a small section of the city called Ophlas.[37] It is probable that a wall separated also Mount Zion from Ophlas; for we find, that when Titus had possession of Acra and the Temple, he had still to bring his engines against the northern wall of Zion;[38] which would not have been necessary if he could have passed at once through Ophlas into that city. Mount Zion was called by David “The Citadel;” it afterwards frequently went by the name of “The Upper City,” in contradistinction to Acra, the latter being frequently styled “The Lower City.”[39]