A region in Los Angeles county that is north of the Santa Monica mountains. Also bordered by the Santa Susana Mountains and the San Gabriel Mountains. Most of the San Fernando Valley is part of the city of Los Angeles but other cities that reside there include Calabassas, San Fernando, Burbank, and Glendale. The city of Hidden Hills is on the edge and may or may not be considered part of the San Fernando Valley. The portion that is part of Los Angeles tried to succeed and form its own city through a vote in 2002 but was unsuccessful. This is the region that the term Valley Girl refers to. The area code is 818 and this is the center of the U.S. pr0n aka porn industry.
The neighborhoods in the San Fernando Valley that are part of the city of Los Angeles are
Arleta,
Canoga Park, Chatsworth, Encino, Granada Hills, Lake View Terrace, Mission Hills, North Hollywood, North Hills, Northridge, Pacoima, Panorama City,
Porter Ranch,
Reseda, Sherman Oaks, Studio City, Sun Valley, Sunland, Sylmar, Tarzana,
Toluca Lake, Tujunga, Van Nuys,
Valley Village, West Hills, Winnetka, and Woodland Hills.
If they had been successful in succeeding from Los Angeles the SFV would have become the 5th largest city in the country. It could hold all of Baltimore, Washington DC, and Boston.
For more information also see sfv and the valley.