Los Alamos is a town in Los Alamos County, New Mexico, United States, that is recognized as the development and creation place of the atomic bomb—the primary objective of the Manhattan Project by Los Alamos National Laboratory during World War II. The town is located on four mesas of the Pajarito Plateau, and has a population of 19,369 as of 2019. It is the county seat and one of two population centers in the county known as census-designated places; the other is White Rock.