Egg Fortress

Robotnik re-located his main base of operations deep into the Special Zone where he could work undisturbed and hidden away from Sonic and the other Freedom Fighters. Robotnik managed to destroy many of the Starposts around Mobius in order to ensure that no one could get into the Special Zone, though a few remain and Sonic managed to salvage one which they used for quick transport around Mobius and into the Special Zone. In this hidden base, Robotnik designed many creations that he used against Sonic and he even managed to lure Sonic into a few, albeit unsuccessful, traps. After Project: Metallix failed, Robotnik re-located his base of operations to his Citadel in Metropolis City and his Special Zone base was left to run on automatic, creating an army of Metallix Badniks. Eventually this Brotherhood Of Metallix decided to take over Mobius and left the base and it was left abandoned and wreaked, adrift in the vastness of the Special Zone.