Partly this is because most audiences will be duped into thinking it's Vermont, where the story takes place, but also because the majority of the film takes place inside a lunatic asylum.
Until the 1970s some governments consigned those people who came under their control to ‘quiet and chronic’ wards in lunatic asylums or hospitals for the insane, and forgot them.
Well-to-do Victorians used to pay to tour lunatic asylums, deriving great amusement from the inmates.
It opened as the County Lunatic Asylum in 1774, one of the first purpose-built lunatic asylums in the country.
There are regular tours of the Castle, but the eighteenth century interiors have all been hideously restored with over-bright gilt and thick pile carpeting so that it all feels rather like an upmarket lunatic asylum.