Gihon did not come down through the middle of the city. The fate of the valleys determines the fate of the hills, and we are perplexed to know which was Mount Zion, which Moriah, and which Akra, nothing seeming to be certain except that the modern Zion (the western hill) is not the ancient Zion, that the Temple (and therefore Moriah) was somewhere within the Haram enclosure, and that the hill to the east of the present Kedron valley is the Mount of Olives. The position of the hills and valleys determines the course of the streams; for the brook Kedron presumably followed the valley of that name, the Pools of Gihon were in the valley of Gihon (if there was a valley of Gihon); and when Hezekiah 'brought the upper watercourse of Gihon straight down to the west side of the city of David,' the direction of the new channel depends on the position assigned to 'the city of David, which is Zion.'[15] On the position and contour of the hills, again, depends the direction of the ancient walls; for these would in general follow the brow of the hill, except on the north side, where the ground made no descent, while Zion appears to have been separately enclosed, so as to need a siege by itself. Until we know the direction of the walls, we know not where to look for the gates and towers, nor for the sepulchres of the kings, which were most of them within the city of David;[16] nor for the Holy Sepulchre, which was _outside_ the gates. A grand point also is the exact site of the temple, which carries with it that of Antonia, which Josephus says was at the junction of the north and west cloisters, and may also help us to find Solomon's palace, and to determine the position of the king's gardens. It must be evident that, while these points remain unsettled, the history of Jerusalem, from David's age to that of Titus, must lack for us the definiteness and vividness which are so essential to its complete understanding. Of theories we have had enough--they are guesses not without a certain value, but guesses almost in the dark--facts are wanted, to test and correct the theories; and these facts the Palestine Exploration Committee promised to supply.