Looks like it's possibly Duxford. If so I was there, albeit at the other end of the airfield (by the M11). I've certainly seen a 16 Spitfire display performing the same routine (wait, how can I call THAT routine?) there a couple of years or so back.
It was an incredible display, with aircraft seemingly coming from all directions, And the sound? Oh the sound!
Thanks for posting the video, Peter. It brought back some wonderful memories. I watched it several times.
I think those Spitfire pilots were having a great time doing that display
I can't imagine them getting out of bed and thinking 'I don't want to go to work today'