Los Alamos (, meaning "The Cottonwoods") is a townsite and census-designated place (CDP) in Los Alamos County, New Mexico, United States, built on the Pajarito Plateau's four mesas and the adjoining White Rock Canyon. The CDP population was 12,019 at the 2010 Census. The townsite or "the hill" is one part of town while White Rock is also part. Technically, both are parts of the same incorporated city/county.