Thanks a lot Lumpine.

My ticket at the moment states that I'm leaving for France from 4s. The reason I want to visit Terminal 1,2,3 is simply because there's a geocache in front of the terminal. I don't need to enter the terminal. I've left terminals before for similar reasons, in Lisbon (went for a 3km walk), Munich, Frankfurt, Copenhagen and other places with similar or shorter stopover times, but never changed terminals for it. If the landside transfer takes 15 minutes and goes every 15 minutes I'll be back in 45 minutes, in theory plus walk to/through customs. But I'm still trying to find out how long the transfer takes and often it goes.