This location exists primarily within the Sonic X continuity.
Information in this article may not be canonical to the storyline of the games or any other Sonic continuity.
Marble Zone is a location that appears in Sonic X comic series published by Archie Comics. It was a location within Dr. Eggman's virtual game world.
After leaving the virtual Green Hill Zone, Sonic the Hedgehog arrived in Marble Zone. Exploring the area as he avoided the various hazards and enemies, he found and rescued Amy Rose. The two then battled a virtual version of Dr. Eggman, and were soon transported to the Spring Yard Zone.