The book of Nehemiah contains the fullest account of Jerusalem topography to be found in the Bible, and casts light on the condition of the city in earlier times, since his work consisted in rebuilding the walls which appear to have stood in ruins, for nearly a century and a half, since their destruction by Nebuchadnezzar. On arrival, in 444 B. C., Nehemiah’s abode was established in the “seat of the governor on this side the river” (Euphrates),[156] which seems to have been a house on the west side of the lower city. Thence he went out by night to view the walls[157]; and, leaving the city by the “Gate of the _Gai_,” somewhere near the present Jaffa Gate, he found the walls of the upper city broken down as far as the Dung Gate at the south-west corner, and the gates burned with fire. Thence he crossed over the hill eastwards,[158] and reached the “Gate of the Spring” near the “King’s Pool.” There is no doubt that the latter is the Pool of Siloam, which--though only a tank--is called a “spring” by Josephus also, because it was fed by spring water through the aqueduct. The “Gate of the Spring” appears to have been at the point where the wall of the upper city formed a re-entering angle, crossing the Tyropœon Valley above the Siloam Pool. Here Nehemiah found masses of ruins, among which “the beast that was under” him could not find footing. He viewed the east wall by going up the _naḥal_ or Kidron Valley, and then returned by the same way to the Gate of the _Gai_ and to his house. [Sidenote: THE WALLS]