I'm not sure where it was exactly, because I got somehow lost in that area. But I think it was west of the place where the Tree Totem can be found. So the Southwestern part of the forbidden lands.
as you're heading towards the forbidden lands from skuldoon, keep to the left (eastern) trail that's heading towards the black swamp. after a few minutes veer off to the left even more and keep walking. you should eventually spot some flames (several burnings pots by a hut).