The Forests of Balor is a vast wooded area past the Mountains of Isgaard. It is likely that these forests are located in a country called Balor. The forests are home to creatures such as Balorian Spiders, which live in the caves deep beneath the forest, and the Cockatrice, a dangerous lizard-like animal. Flora growing in the forests include the Mortaeus tree, on the roots of which the Mortaeus flower grows.
This was where Arthur and Nimueh met when Arthur went on a quest to retrieve the Mortaeus flower in order to save Merlin from a deadly poison, on the way Arthur encountered Balorian Spiders and a Cockatrice. Nimueh betrayed him at the end, leaving him to die in the cave, but Merlin's guiding light saved him (The Poisoned Chalice).
- It is highly likely that Nimueh's caves were located in that area, as she seemed to know these caves well enough to guide and trap Arthur at a dead end.
- It is revealed in the novelisation of Valiant that the Serpent Shield contains snakes taken from this forest.