Xi'an city wall symbol of the greatest of Tang.

Xi'an is one of the few cities in China where the imposing old city walls still stand. Built in 1370 during the Ming dynasty, the magnificent 12m-high walls are surrounded by a dry moat and form a rectangle with a perimeter of 14km. Most sections have been restored or rebuilt, and it is possible to walk the walls in their entirety in a leisurely four hours (or around two hours by bike, or at a slow jog).