The Forgotten Forest is a location on Eternia. It is home to Skytree and is protected by the Treeprechauns, including Tullamore.
Long ago, in a time now forgotten, a man who held the title of Man-At-Arms saved the Forgotten Forest, including the ancient Skytree, from the Witches of Fire. Skytree remained in the debt of all the Men-At-Arms that followed him.
Granamyr sent He-Man and Teela to the Forgotten Forest to chop down Skytree in exchange for telling them how to reverse a spell that had turned the current Man-At-Arms into a crystal statue.