Metropolis City High Security Prison is a highly fortified fortress-like building with maximum security. It is run by the Prison Governor.
Grimer Wormtongue was incarcerated in Metropolis City High Security Prison sometime after Dr. Robotnik's disappearance on the Floating Island. However, Grimer was somehow able to take control of the prison in secret and force the Prison Governor to be his lackey. From within the prison, Grimer established a base of operations where he investigated Robotnik's whereabouts while the Prison Governor covered for his activities.
From within the prison, Grimer would sent a Knuckles Metallix to retrieve Sonic the Hedgehog. While Sonic was unconscious, Grimer extracted his knowledge on Robotnik's wereabout via a memory scan. After recovering, Sonic contacted the Prison Governor to check up on Grimer. However, the governor would lie about Grimer's status on behalf of the villain. Later, from within the prison, Grimer was able to remotely hack the Kintobor Computer and make it trick Sonic into going to the Metropolis Zone where the Kintobor Badnik would attack him. While Sonic was busy dealing with the rogue Kintobor Computer and restoring it to normal, Grimer secretly implanted a surveillance software into the Kintobor Computer's system, allowing him to monitor Sonic's every move.
When Sonic was being chased by a smart missile sent by the Trickster, the missile broke Mr. Fry out of the Metropolis City High Security Prison, whereupon the monster attempted to defeat Sonic, but failed.