An ancient name for Mirkwood. The Greenwood, otherwise known as Greenwood the Great, was originally inhabited by Silvan elves descended from some of the Nandor that decided to remain by the Anduin.

In the Third Age, Greenwood was the largest forest still remaining in western Middle-earth. It was over 400 miles from north to south and 200 miles across its widest point, where the old Forest Road made a path from Wilderland to the River Running. In the north-east dwelt the elves of Thranduil’s realm, while scattered settlements of woodmen were present in the south-west.

See Mirkwood for the forest's later history.
Encyclopedia entry originally written by atalante_star