there was an out station of Boscombe Down in Libya
That would be Idris.
I've also taken part in A&AEE trials in Karup in Denmark, Yuma and El Centro in Arizona and Brunei. Never having been on Rotary icing work I've missed out on the long trips to Canada and Norway. As for ranges in the UK I've also used Studland Bay and Porthkerris on the Lizard.