San Fernando Road (officially known as Business Loop 5) is a major street in the city and county of Los Angeles. It starts off in Castaic as The Old Road, passing through Santa Clarita and the Newhall Pass, whereupon its intersection with Sierra Highway near the junction of the Golden State (I-5) and the Antelope Valley (SR 14) Freeways, it becomes San Fernando Road. San Fernando Road then passes through the Sylmar district of Los Angeles and the city of San Fernando. It re-enters the city of Los Angeles at the intersection with the Ronald Reagan Freeway (SR 118) in the Pacoima area, where it parallels Interstate 5. Like Laurel Canyon Boulevard to the west in Sun Valley, it passes through rock quarries and one of the last remaining open spaces in the San Fernando Valley.