We flew over Tellytubbieland today coming back from Bidford to North Weald - it is very close to Long Marston. Follow the runway out to the west and there's a farm with a large grain silo. Its in a corner of a field adjacent to the farmyard. There's a load of portacabins and other temporary buildings and this strange astroturf covered mound. (I always like to take a turn around it at 1,000 feet, just in case they're filming!)