Sonic's Secret Underground Base

Originally this was the home to the kindly Doctor Ovi Kintobor, who had a vast underground laboratory stored down here along with his Retro-Orbital-Chaos-Compressor. After the accident that caused him to become Doctor Ivo Robotnik, Sonic, Tails and the Freedom Fighters used the lab as their secret base and hid from Robotnik for many years. They installed Kintobor’s personality from a Golden Ring and onto a computer system to allow them to keep track on Robotnik’s forces. When Sonic and Tails captured Robotnik on the Floating Island they brought him to their base and held him captive, however the duped Knuckles was able to track Robotnik and rescue him, this revealing the location of the base. After Robotnik’s initial defeat on the Floating Island he enacted his revenge by destroying the base and driving Sonic and his friends out into the open, where they continued to hide as “Bob Beaky’s Travelling Circus”.