First appears in: The Twin Fury
Ilyrion Park is a natural preserve located within the ancient elven capital of Ilyrion on Valaralda. Standing as a bastion of nature against the encroaching urban sprawl, it is described as being "mostly forest, the park was, land that hadn’t been converted into houses from its natural state".
The park becomes the site of a miraculous, world-altering event when the celestial object Guruthos first arrives in the sky. Aten ventures into the park's undergrowth and is stunned to find that the normal maple tree in the center of the park has spontaneously mutated. He observes that it is now "huge in every dimension: the trunk was hundreds of feet wide, and it had to be at least a thousand feet tall... It was almost as if the hand of God had reached down to pluck this one tree out of oblivion, raising it to new stature". This marks the sudden, explosive birth of the first Prime Trees on Valaralda.