Arctic Zone

The Arctic Zone is a location that appears in the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics. It is an area inside a cave that the Arctic Freedom Fighters took shelter in to hide from Dr. Robotnik.

History
They built it by collecting discarded parts that Robotnik tossed aside over time. When it was finished, the Arcitc Freedom Fighters used it to control the enviroment in the cave so they could have the same climate year-round. It is likely that the project was abandoned when the Arctic Freedom Fighters relocated to the Northern Tundra.