North Salem is a town in the northeastern section of Westchester County, New York, United States. The town, incorporated in 1788, is a suburb of New York City, located approximately 50 miles north of Midtown Manhattan. As of the 2020 census, North Salem was recorded as possessing a population of 5,243 people living on a land area of 21.37 square miles.

X-Mansion and Xavier Institute are the common names for a mansion and research institute appearing in American comic books published by Marvel Comics. The mansion is depicted as the private estate of Charles Francis Xavier, a character in X-Men comics. It serves as the base of operations and training site of the X-Men. It is also the location of an accredited private school for mutant children, teenagers, and sometimes older aged mutants, the Xavier Institute for Higher Learning, formerly the Xavier School for Gifted Youngsters. The X-Mansion is also the worldwide headquarters of the X-Corporation.