High on the side of San Bruno Mountain, giant white letters spell out "South San Francisco The Industrial City", a hillside sign put up in the 1920s and still the first thing most people notice when they arrive. It tells you the town's story: this was a place of meatpacking, steel, shipyards and factories, the working neighbour to the grand city to the north, and it has kept that practical, unpretentious feel even as its industries have changed.
The biggest change came in 1976, when a young company called Genentech set up here, and South San Francisco became known as the birthplace of the biotech industry. Today its eastern shoreline, along the bay, is packed with labs and research campuses, and the town is one of the world's great centres of biological research. San Francisco International Airport lies just to the south, and planes roar low over the bay all day.
San Bruno Mountain, rising above the town, is a surprising island of wild land in the middle of the urban peninsula. It is a state and county park, with grasslands, coastal scrub and rare species, including the tiny mission blue butterfly, and its trails offer views over the bay, the city and the ocean. When the summer fog rolls in from the Pacific, it pours over the ridge like a waterfall, and the temperature drops by ten degrees in minutes.
As the finish of a Big Sur ride, it marks the end of one of the great coastal rides of the world. Highway 1 from Big Sur runs north past Monterey, Santa Cruz and Half Moon Bay, along cliffs and beaches, and the last stretch through Pacifica uses the Devil's Slide tunnels, opened in 2013 to replace an old road that kept falling into the sea. From there, you cross over the hills into South San Francisco. Traffic builds as you get closer to the city, and the fog can make the coast cold and damp, even in summer.
Fuel, food and services are easy to find, and there are good Filipino, Mexican and Chinese restaurants in the town. Pull over somewhere you can see the sign on the hill, and enjoy the fact that you have ridden one of the world's great roads.