Some thoughts, you don’t have to answer them all
But it might ring a bell by fellow searchers.
I have no time nor lead to start searching.
Although you can find birch trees all over Europe.
This has a bit of Nothern Europe look.
German or perhaps Sweden?
Am I at least on the right continent?
Military use on a grass strip with civil weekend use?
Which country has that kind of bases?
Fairly big number of GA planes.
So an ?yearly? Fly-in event known by much pilots?
Those 2 “Piramid” shaped buildings in the back in the middle.
Are those agricultural storage sheds?
SLB