The Xavier Institute, Salem Center, Westchester County, New York State, (former) The Alley (beneath Manhattans surface), X-Factor Is sentient starship
Serval Industries, Virginia; formerly X-Factor Investigations Headquarters, Starjammer; Xavier Institute for Higher Learning, Salem Center, Westchester County, New York; Genosha; X-Factor HQ, Washington D.C., Maryland; Mutant Research Center, Muir Island;