Sonic Chronicles: The Dark Brotherhood
Green Hill Zone (グリーンヒルゾーン Gurīnhiruzōn?) is the first area that appears in Sonic Chronicles: The Dark Brotherhood. In this game, Green Hill Zone takes on a more realistic look, adding rocky textures to shuttle loops and other gimmicks, while still retaining certain features, such as checkered walls in certain areas.
The storyline of the game begins in Green Hill Zone, with Sonic traveling through the area to see Tails in Central City. The animals of the Zone have become strangely belligerent and attack on sight; this behavior was later discovered (by the beleaguered Doctor Madden) to have been caused by signal-generating machines hidden around the area; although whether these devices are Dr. Eggman's doing, or Shade's, is never revealed.
The team later have to search Green Hill Zone for some of Eggman's hidden bases, which can be accessed only after the party recruits flying characters such as Tails and Rouge. At the end of Chapter 3, Dr. Eggman himself is finally discovered, operating out of the last of these underground hideouts.