The Longest Journey Edit
Northernmost point of the Northlands (as region rather than continent). Abnaxus has a book on his shelf entitled Surviving the Border Mountains, perhaps because he himself is from beyond the mountain range.
It is possible that its highest peak is Mount Tireney, mentioned in The Silver Spear of Gorimon as the only place a particular white metal could be found. As this ore was used to forge a weapon capable of harming the Mother, it is possible that she later made it her home, so as to keep a closer eye on her one weakness.
Before the release of Dreamfall it was revealed that after the events of TLJ April and Crow travelled into the Border Mountains, and it seems likely to be the place she abandoned him 2 years later. If the piece of concept art entitled "Northlands" depicting a figure that appears to be April among the mountains is indeed of the Border Mountains, the similarity of the landscape may confirm that the White's lair was indeed in the Northlands mountain range.