The little archaeological work that has been done on the western slope of the City of David tends to substantiate this view. In 1927, J.W. Crowfoot excavated a wide trench, oriented from east to west, across the Tyropoeon Valley that separates the City of David from Mount Zion on the west. He uncovered a massive structure at the lower edge of the western slope of the City of David, which he identified as a gatehouse constructed in the Bronze Age and used until the Roman period. In my view, however, analysis of the data indicates, that this is probably a massive substructure of a large edifice that was not preserved, rather than a city gate. The construction of such a substructure was necessary in view of the steep slope and narrowness of the ravine at this spot. In any event, it appears that the structure postdates the Persian period. I will be publishing my detailed analysis of the data in a scholarly journal in the future. While it may be difficult to determine the precise function of the structure this substructure was built to support, it is clear that it was not a gatehouse as suggested by Crowfoot. In short, Crowfoot found no evidence for a First Temple wall on the western slope of the City of David.
Recently Meir Ben-Dov independently reached similar conclusions.
I refer to excavations on the southwestern hill, Mount Zion, the Jewish Quarter of the Old City, the Armenian Quarter and the Ottoman Citadel.
I am indebted to Axel Knauf for this suggestion.
Steven Runciman, The Fall of Constantinople 1453 (Cambridge: Cambridge Univ. Press, 1965), pp. 9–10.