[link|http://emuseum.mnsu.edu/archaeology/sites/middle_east/jericho.html|Jerico may be 10000 years old.]
While trenching downward through the site she uncovered the first walled city along with a number of houses and courtyards that had been constructed over 10,000 years ago, during the Neolithic.
I had heard somewhere (perhaps the The Ascent of Man program) it is the oldest city.