Fortress Auchindoun was located northwest of the old Bone Wastes (the location of the draenei necropolis of Auchindoun) on the southwest edge of Hellfire Peninsula, roughly near Shattrath. It was located near the fork between three large rivers. Kurdran had located the hidden Fortress of Auchindoun and the battlements that served as stronghold to the Bleeding Hollow clan. Alleria's rangers had reported that they had seen a massive force moving towards the north, and suspected that those troops were staging for another attack upon Azeroth. The Alliance forces launched a raid against Auchindoun and razed the Fortress of Auchindoun to force the Horde army to retreat, or to be cut off and destroyed. They then escaped before they were caught by the northern orc forces. In the aftermath, the blazing ruins of Auchindoun were surrounded by arcane powers, that summoned Khadgar to the dark lands of the orcs. While examining the remains of the great fortress, Khadgar learned the location of the Book of Medivh and Skull of Gul'dan.
Fortress Achindoun and the burial ground of Auchindoun are likely intended to be the same place. If so, it is likely a retcon.