Muir Island is an island on the coast of Scotland. It is known mostly for the research facility that is located on the small island.
Muir Island was created by Chris Claremont and Dave Cockrum and first appeared in X-Men #104 (1977).
Major Story Arcs
The research facility was founded by Moira MacTaggert as she created it for her destructively powerful mutant son, Proteus. The knowledge contained in this facility includes the knowledge of many mutants and their abilities as well as mutant-related concerns.
It was here that Professor X stored information on how to kill members of the X-Men, if the need ever arose and it has been a base of the X-Men team, Excalibur. It is also where Magneto and Spoor were imprisoned.
Members of its staff have included Rahne Sinclair, Rory Campbell, Tom Corsi, Sharon Friedlander and James Madrox. It has also been seen as a target for many including the Acolytes, Shadow King, Galactus, the MLF, Spiral, Bastion, Legion and Proteus.
The facility was destroyed by a Shadow King-possessed Legion and after it was rebuilt it was once again destroyed, this time by Mystique and Sabretooth.
It was the location of several X-Men deaths due to the Inhuman's Terrigen Cloud.
Earth-1610 (Ultimate Universe):
In the Ultimate Marvel Universe, Muir Island's facility is still led by Moira MacTaggert but it is a hospital for mutants rather than a research facility.