Iron Lock Prison

Iron Lock Prison, located in the Dark Swamp, was at one point in time a correctional facility used by Mobotropolis. It was built in 1543, Mobius Timeline, long before the city itself was founded, and its original purpose is now unknown. It was abandoned a century ago due to its outdated conditions and changes in the city's development, and was replaced by a more modern facility.

Since its abandonment, Iron Lock has deteriorated significantly due to its age, the swamp's conditions, and Dr. Robotnik's pollution.

At one point, Sally found evidence that King Acorn had passed through the prison at some point in time, but it remains unknown when this was or the king's exact intent.