city information and pictures about Castro Valley unincorporated urban community with discussion forum, map, real estate and Castro Valley unincorporated urban community population & photos
Castro Valley, unincorporated urban community, Alameda County, western California, near the city of Oakland and San Francisco Bay. It is mainly residential. The site was part of a Mexican land grant made in the early 1840s to Guillermo Castro, hence the community's name. Population 44,011 (1980); 48,619 (1990); 48,619 (1996 estimate).
