"LAYERS OF ANCIENT JERUSALEM"
I usually don't refer my readers to a magazine but here's an exception: In the January/February 2012 Biblical Archaeology Review there is a splendid article about the Western Wall Plaza Excavation.
To quote briefly "Actually the site of he excavation was outside the city until the eighth century B.C.E. It is located on the northeastern slope of the so-called 'western hill'; In King David's time, Jerusalem was confined to the 10-12 acres ridge south of the Old City known even today as the city of David. Then Solomon extended the city northward where he built the Temple on a much smaller enclosure than the one built by Herod the great a thousand years later. Not until King Hezekiah's time, in the eighth century B.C.E. was the city exteded west to the western hill -- the present area of Mount Zion, the Armenian Quarter and the Jewish Quarter of the Old City."
The details of the dig and the illustrations are marvelous. Possible to read http://www.bib-arch.org/bar/article.asp?PubID=BSBA&Volume=38&Issue=1&ArticleID=6