The construction of Hadrian's Wall as shown at the end of the film is not historically accurate. A wooden wall was constructed first with a deep ditch on either side. One of the ditches should be visible as the characters approach the wall but it is not. The stone wall shown being constructed was not added until later and then it was constructed in sections. It did not become a continuous stone wall until some years later. In addition, the stone wall shown is not wide enough. Hadrian's Wall is around 2 meters wide at the top and even today you can comfortably walk on top of it.