The East Forest is a lush hill area surrounded by mountains, with widespread trees and small boulders. There are vines creeping up the trees, and smaller bushes and wide-leafed plants that dot the landscape. Within the forest is a former tin house that served as Metal Sonic's hideout.
While framing Sonic for thefts, Metal Sonic hid in the East Forest. However, Sonic and Knuckles tracked Metal Sonic to his hideout, forcing the robot to fight the duo. Though Metal Sonic took out Knuckles, he was at a disadvantage against Sonic, so he used Dr. Eggman's Particle Accelerator to boost his power and followed Sonic out of the East Forest.