Hah, good one! I almost said Winter Palace, but then it hit me. Chateau d'Onterre library.
Very good, correct! I had never seen that book there before, until I went looking for a fake-out shot that would look like Trespasser.
Yep, Frostback Basin. Maybe next hint. You definitely go next to this place if you follow the quest.
C'mon, I need more than that. I went next to a lot of places in JoH. I mean, in the side-quest Up and Away you have to chase Runa all over the cliffs and stuff ...
Wait. No, that was a sun graffiti, not an owl. Or was there an owl there? I don't remember!