Beginning at the remarkable neck of land near the present Jaffa Gate a wall ran eastward along the northern brow of the hill, and in the line of the Causeway, and ended at the west cloister of the Temple. This was the north wall of the Upper City. That city had a wall all round it; and on the west, south, and east the wall simply followed the brow of the hill. From the Jaffa Gate it ran southward (facing westward) along the brink of the Valley of Hinnom, by Bethso (the Hebrew term for Dung place) to the Gate of the Essenes. At the south-west corner of the hill an escarpment of the rock was noticed by Robinson; was further traced by Mr Maudslay, who in 1872 found there a tower, reached by rock-cut steps; and is clearly marked in Conder’s plan. From this corner the wall faced the south for a while, and then, according to Josephus, made a bend above Siloam; and this must have been, as Mr Lewin points out, a bend up the Tyropœon Valley, along the edge of the High Town (to the Causeway), and then back again along the edge of the Low Town on Ophel (until it joined the Wall of Ophel discovered by Warren). The wall from Siloam, we learn from Josephus, bending there, faced to the east at Solomon’s Pool, and holding on as far as the place called Ophla, joined the eastern cloister of the Temple.[27] The eastern cloister of the Temple--_i.e._, the south-eastern angle of the enclosure--was, in Josephus’s day, coincident with the south-east angle of Solomon’s palace of earlier time; and the city wall which joined it was the Wall of Ophel itself. According to this description Solomon’s Pool was in the Tyropœon Valley, between the two walls of the High Town and the Low Town. Probably at a very early period many houses were built in this valley, and it became an intramural suburb. In view of war it would be deemed necessary to protect it; and for its defence the most obvious plan would be to build a dam or a wall athwart the valley. Such a work would greatly strengthen the city itself, by preventing all access up the valley, especially if the mound or wall was aided by a castle at the Ophel end of it. We shall see reason to believe that the dam and the castle were built and were called Millo and the House of Millo. The suburb thus became immured in the city, but continued to be called the Suburb; and we read that the west wall of the Temple enclosure had two gates leading to the Suburb (Josephus, “Antiquities” xv. 11, 5; 1 Chron. xxvi. 16, the gate Shallecheth).