This castle, occupied by Iuz’s forces, is a watchpost over the Bandit Lands eastward. It takes in supplies from those lands, such as they are. The resident priests and mages of Iuz form a strike force together with urzun orcs and babau and they go trouble-shooting in the western Bandit Lands when required. The castle itself is a rather precarious edifice, for it is built on rocky terrain that contains many rifts including some below the castle itself. That such terrain should be found in plains land on the banks of the Ritensa is odd enough to suggest magical forces at work, and indeed they have in some way been used within the castle.
The castle records were lost during the wars when the mage who built the castle, Yazmurden, abandoned it. Thus, they do not record the details of how to avoid the one hazard of the teleport rooms. The very few orc survivors of such a mishap reported aboleth and illithids in the rift, so no-one is keen to explore them further.
Carl Sargent. Greyhawk Adventures, Iuz the Evil, 1993