In November 1983, Will encountered the Monster on Mirkwood and ran through the forest to his home. He was abducted by the Monster, and the police found his bike by the road the following day. Disappointed with the police's efforts, Will's friends went to Mirkwood themselves, where they found Eleven in the nearby forest.
Mirkwood is located where the roads Cornwallis and Kerley meet and goes past the Hawkins National Laboratory. It is in close proximity to both the Byers house and the Harrington house, with only a forest separating them.
The name Mirkwood originates from a forest in Old Norse mythology, where it was called Myrkviðr. It means "dark wood" or "black forest." Inspired by the mythology, Mirkwood is also a forest in The Hobbit and The Lord of the Rings by J.R.R. Tolkien where the character Legolas originated. It used to be called Greenwood the Great before it was taken over by the evil necromancer Sauron.