Green Hill is a location that appears in the Sonic the Hedgehog comic series and its spin-offs published by IDW Publishing. It is a region on Sonic's world. As the name implies, it is a place covered in bright green grass.
Green Hill is a picturesque mountain region with brown mountains in the horizon and flat blocky hills with green grass on top of them. In addition, the soil is brown with checkerboard patterns. Also, among the various hill shapes are some broken shuttle loops.
The region used to be dominated by a large blue lake, but it has since been replaced with a desert of sand.
After Sonic the Hedgehog managed to defeat Dr. Eggman at the end of the Eggman War, the doctor disappeared. However, his robot forces remained. Without a leader to give them orders and/or direction, the robots stationed in Green Hill would wander around aimlessly being a big threat to themselves and attacking anything they came across until they came under the control of Neo Metal Sonic, who made them more cohesive.