Mirkwood

Mirkwood is a name used for two distinct fictional forests in J. R. R. Tolkien's legendarium. In the First Age, the highlands of Dorthonion north of Beleriand were known as Mirkwood after falling under Morgoth's control. During the Third Age, the large forest in Rhovanion, east of the Anduin in Middle-earth, was called Mirkwood after falling under the influence of Sauron. Before that, it was known as Greenwood the Great. The term Mirkwood is taken from William Morris, influenced by the forest Myrkviðr of Norse mythology. Projected into Old English, it appears as Myrcwudu in Tolkien's The Lost Road, as a poem sung by Ælfwine.

Forests play an enormous role throughout the invented history of Tolkien's Middle-earth and are inevitably an important episode on the heroic quests of his characters. The forest device is used as a mysterious transition from one part of the story to another.