Oh. Windsor Resort, in England, just west of London. Not far outside the M25, sort of near Slough.
I think the Flintstones set is pretty neat, even though the house walls are a little too flat. The best feature, I think, is the Brontosaurus ribs which can keep the car on its side, like in the old intro. I think the car wheel cylinders were a standard piece before. My non-Samsonite Leaning Tower of Pisa has one (i.e. a pair of half cylinders) as its central core. (LEGO sure was right to withdraw the Leaning Tower model soon after introduction, however; it's terrible--distinctively five-sided instead of circular; having only 10 columns per storey instead of the real 24 or so; it seems the LEGO design was mostly an exercise in producing a leaning tower).
Anyway I wonder if the Flintstones set got started when a designer picked up a pair of those cylinders, and realized they could make the Flintstone car around them.