The discovery in the 1970s of the rather unobtrusive 23-foot-thick foundations of an Old Testament city wall was hailed as one of the most important archaeological finds in the Jewish Quarter. The wall was built in 701 BC by Hezekiah, King of Judah and a contemporary of the prophet Isaiah, to protect the city against an impending Assyrian invasion. The unearthing of the Broad Wall -- a biblical name -- resolved a long-running scholarly debate about the size of Old Testament Jerusalem: a large on-site map shows that the ancient city was far larger than was once thought.