Dorthonion
From Tolkien Gateway
A highland region lying immediately to the north of Beleriand; overrun by Morgoth in the Dagor Bragollach, after which it was known as Taur-nu-Fuin.
A highland region lying immediately to the north of Beleriand; overrun by Morgoth in the Dagor Bragollach, after which it was known as Taur-nu-Fuin.