California State Route 13, also known as Thornhill Drive, is a state highway located in the San Francisco Bay Area. It runs approximately 6.5 miles, connecting the cities of Oakland and Berkeley. The route primarily serves as a scenic drive through the East Bay hills, offering views of the surrounding landscape. The highway begins at the intersection with California State Route 24 in Oakland and ends at University Avenue in Berkeley. It is known for its winding roads and access to several parks, including Tilden Regional Park and Redwood Regional Park, making it popular for both commuters and recreational drivers.