FYI: The only castle that the Python group was allowed to use for their seminal film was Doune Castle in Scotland. Partly do to restrictions (Cleese said other venues would not allow filming a comedy), and strict budgetary constraints, Doune Castle played MANY roles throughout the film.
The whole video is really worth watching, but I'll skip here to one of the more interesting parts ...
The whole video is really worth watching, but I'll skip here to one of the more interesting parts ...