|Real Name||Asteroid M|
At some unknown point, Magneto formed Asteroid M. It is unknown whether this is an actual asteroid from space or simply a large rock and called it an asteroid.
The base seen in the series is based on the third version of Asteroid M. The previous two were merely bases for Magneto during his criminal activities. The third also served as a base during his crimes but was later used as a base for peace, taken over by Cortez, and later destroyed. It was the most recent version before X-Men began.