This cold northern wood is home to many humanoid tribes as well as other monsters. Deep in this wood, a hag of enormous power is rumored to be building an army of trolls to conquer the southlands.
This hag, Hettie Weedlock, is in fact planning to do just such a thing. She has already established what amounts to a state, hidden deep in Far Borea, with her as the Supreme Cackle. Her standing army does indeed include some trolls, but also other humanoids such as bugbears and goblin kin.
Far Borea is one of those places where you aren’t sure if you’re in the normal world or in the Feywild, and there are many portals to the nastier, fen-like parts of the Feywild hidden in the woods.