The so-called 'Mach Loop' in North Wales is used a lot for training, and there are lots of youtube vids of different aircraft flying 'The Loop'
We were on holiday is Scotland once around the Cairngorms, and saw a C130 doing something similar - it was actually flying in a valley below us.
“O Lord God, let me not be disgraced in my old days.”
'We few, we happy few, we band of brothers'