great black castle of the orcs

[Havard]

Another possibility could be in the Stormkiller Mountains, maybe on the Stealhead River or Mogok River. Perhaps this is where Oberstar is being held?

Giving this some more thought, I am leaning towards this location. According to Arneson, his players never wanted to adventure anywhere near the Egg of Coot. The Stormkiller Mountains seems to be the main center of Orcs and such outside the Realm of the Egg. Not counting the Blackmoor Dungeon of course. Speaking of which, I also have a theory about a secret tunnel leading from the Stormkiller Mountains to the Blackmoor Dungeon. This would help explain why the King of All Orcs can be encountered below Blackmoor.

-Havard