It will come up soon, but they are basically a wasteland, the remnant of three Gods fighting. That's were Enki, the gods of magic whose eye adorn the sigil of House Widale, and Ninkasi, battled Hanbi an evil demi-god.
They were trying to not, you know, destroy the whole lang when Enki was slain. Ninkasi, knowing that he could not old up alone against Hanbi, unleashed his full might for a single blow, that caused a whole zone to be...well dead.
It's situated mostly to the south of the Wood Elve land, a natural border between them and the Sultanate. The air is toxic, there is very limited food, and a lot of weird monsters inhabit it. That's were the demons choose to place the birthing pools of the modified orcs, that are homunculus now, soulless being created by foul magic.