Dark Sun: The Scorched World of Athas
The being calling itself Rafernard claims to have created the forest as a first step on the path to restoring Athas. Rafernard was revealed to be a disguise of Abalach-Re and the entire forest was a lure for the pilgrims to fuel her transformation into a Dragon.
The forest contains a central plaza where a Tree of Life was found intertwined with a ruined tower. The tree was destroyed and tower transformed into a during Abalach-Re’s metamorphosis. Beneath the tower, now buried by rubble and ash, is a pyramid structure.