Mount Mobius is a location on Mobius. Originally an impressive natural feature, the mountain was taken over by Doctor Robotnik and the Veg-o-Fortress, the first major Badnik Processing Plant, was built on top with the whole rock formation becoming Robotnik's part-time base. Sonic the Hedgehog, the other Freedom Fighters and the Emerald Hill folk were to be taken there by Trusk in order to become Badniks, but were saved by Captain Plunder and the Sky Pirates.
The current status of Mount Mobius is currently unknown. It is likely that the area returned to its former glory after Robotnik's final defeat.