Hidden Hills is a city and gated community in Los Angeles County, California. It is located next to the city of Calabasas and is located in the west of San Fernando Valley. It is notable for being home to many actors and celebrities.Geography and historyHidden Hills is in the southern Simi Hills Transverse range near the Santa Monica Mountains.The community was designed and developed in the 1950s by A.E. Hanson, a renowned Southern California landscape architect and planned community developer. His earlier projects included Rolling Hills and Palos Verdes Estates, and the 1920s Beverly Hills Harold Lloyd Estate 'Greenacres.' It is a gated residential community with a total all land area of 1.7sqmi. An elementary school is publicly accessible at one of the three gates to the community. The city has a summer camp for children, community and children's theatre programs, annual parades, carnivals, parties, welcome wagon, snow days, and weekly community-wide barbecues all summer long.Hidden Hills is bordered on the north by the nature reserve and greenbelt of the Upper Las Virgenes Canyon Open Space Preserve, a park with miles of equestrian, hiking, and mountain biking trails. Nearby to the south is the pioneer Leonis Adobe National Historic Landmark, with gardens and a historical Museum. It's across the historic El Camino Real of the Spanish Las Californias and Mexican Alta California eras, now U.S. Route 101.