Calabasas (“Pumpkins”) is a city in Los Angeles County, California. It is located in the hills west of the San Fernando Valley and is in the northwest Santa Monica Mountainsbetween Woodland Hills, Agoura Hills, West Hills, Hidden Hills and Malibu, California. As of the 2010 census, the city population was 23,058, up from 20,033 at the 2000 census. The city was formally incorporated in 1991. It is noted for its wealthy residents and gated neighborhoods.
The Leonis Adobe, an adobe structure in Old Town Calabasas, dates from 1844 and is one of the oldest surviving buildings in the greater Los Angeles area.
Safeguarding the environment and the protection of open space has been a longstanding priority for residents of Calabasas. The city played a vital role in the 10-year battle to save Ahmanson Ranch, a 2,983 acres (12.07 km2) property in the Simi Hills in Ventura County nestled at the western edge of the San Fernando Valley, from development. The land was ultimately sold by Seattle-based Washington Mutual to the Santa Monica Mountains Conservancy in late 2003 for $150 million. Ahmanson Ranch is now known as the Upper Las Virgenes Canyon Open Space Preserve and is protected from further development.