Muir Island is a small, island off of the northern coast of Scotland.
Muir Island’s significance stems from the fact that it is the home of Earth’s largest and most comprehensive mutant research complex, the Mutant Research Center, founded by Dr. Moira MacTaggert. Originally, she created the facility to help her son, Kevin (a.k.a. Proteus), an extremely powerful and destructive mutant.
Muir Island’s facility holds a wealth of knowledge on various mutants, their abilities, and other mutant-related issues and concerns. It was also once the home base of the X-Men spin-off superhero team Excalibur. Nor’Easter was working for Moira for a brief time.
Mutant research facility partially sponsored by Professor X, held mutant criminals as needed. It was the home for the Xavier Academy Ireland while their mansion was being built.