York is a walled city in northeast England that was founded by the ancient Romans and then invaded by Vikings (Ivar The Boneless). The City Walls form a walkway on both sides of the River Ouse. The Monk Bar gate houses an exhibition tracing the life of 15th-century Plantagenet King Richard III, but far more importantly it is home to the Rowntrees factory, creators of the Kit-Kat back in the 1930s.