Last year it was £22.50 - before that was prior to my joining, so I don't know how the charges have changed over the years.
Oh no!
I can remember my visits to the factory, long before the Visitors Centre. You turned up, called in at Reception, were given a single sheet of paper, shown where to start and then just told to ‘follow the line on the floor’ - unaccompanied and no charge!
