I Need to Know...

When I'm  flying to Britain it seems to have become a personal tradition to blip something from the lovely Terminal 2 at Arlanda.
Here is a doorway in the long corridor linking the gates from which SAS fly to the world.
Where does it go? Who is it for? What is inside? The answers to all these questions seem to be on the "need to know" principle, and apparently I don't need to know!