Suffolk.....
Has an abundance of Military based research and flight, what with Martlesham, Bawdsey, Parham, Bentwaters and Orford Ness, and the often overlooked RAF Woodbridge, with its "incident": https://en.wikipedia.org/wiki/Rendlesham_Forest_incident
Many other sites can be walked around too. I spent may an afternoon walking around the remnants of http://pillboxesinsuffolk.blogspot.com/2011/04/gci-radar-trimley.html