Sun Valley is a neighborhood in Los Angeles, California in the San Fernando Valley region. The neighborhood is known for its overall youthful population. There are three recreation centers in Sun Valley, one of which is a historic site. The neighborhood has thirteen public schools—including John H. Francis Polytechnic High School and Valley Oaks Center for …Sun Valley is a neighborhood in Los Angeles, California in the San Fernando Valley region. The neighborhood is known for its overall youthful population. There are three recreation centers in Sun Valley, one of which is a historic site. The neighborhood has thirteen public schools—including John H. Francis Polytechnic High School and Valley Oaks Center for Enriched Studies —and four private schools.