Taur-nu-Fuin
Later name for Dorthonion, after its conquest by the armies of Morgoth. At the time it bore the name, it was a desolate forest from which people and animals had fled, inhabited only by wandering bands of Morgoth's monsters and orcs.
It was a plateau raised above ground, and may have survived the flooding of Beleriand as the island of Tol Fuin.