
The Age itself consists of an incredibly large 400 ft. tall tree in the middle of a great expanse of ocean. There are three distinct eco-systems within the tree, starting from the top and going down: Deadwood Ridge (Upper, Middle, and Lower), The Forest, and The Swamp.
Edanna was one of the lesson-Ages Linked to from J'nanin. Atrus wrote the Age to illustrate the concepts of nature and the inter-dependence of elements within the environment; specifically, Nature Encourages Mutual Dependence.
This was also the first Age in the Myst franchise of games to be completely Nature based, thus there are no machines or other man-made objects present, save for the imager Atrus installed to continue his sons on their path of learning the concepts of writing an Age, and a trap used by Saavedro to collect animal skins. The original message from Atrus is lost, due to Saavedro recording his own over Atrus' original.