The X-Mansion is the common name for Professor Xavier's mansion. It is the base of operations and training site of the X-Men and the location of a school for mutant teenagers, the Xavier Institute for Higher Learning, formerly Xavier's School for Gifted Youngsters. It is also the worldwide headquarters of the X-Corporation. Its address is 1407 Graymalkin Lane, Salem Center (part of the town of North Salem), located in the very northeast corner of Westchester County. The school's motto is "mutatis mutandis."

Our goal is to teach mutants to use their powers for the benefit of mankind and not evil. Those who graduate can stay and join the X-Men or become useful members of society, but be warned that a war is coming. The forces of Magneto and his Brotherhood are always on the attack and hurt the cause that we fight for.