Ai - Et-Tell

The site of et-Tell is a prominent ruin that is usually identified as biblical Ai. Archaeological excavations though have shown that Ai was inhabited from 3000-2400 B.C. and again after 1200 B.C., but not during the time of Joshua's Conquest (1400 B.C.). Resorting to a "late date" theory of the Conquest does not solve the problem. [Bible Places]

Link: http://www.bibleplaces.com/ettell.htm