In Comics
Giant-Size X-Men #1 - Deadly Genesis
The Amazing Spider-Man #149 - Even If I Live, I Die
Base
(current) Professor Charles Xaviers Institute for Higher Learning, Salem Center, Westchester County, New York (former) Muir Isle, Scotland,; a loft in Soho, Manhattan, Ust-Ordynski Collective, Lake Baikal, Siberia, U.S.S.R., X-Men Headquarters in Austra
Not Available