There is a part of the coast highway (Highway 1) that runs along the cliffs between my town and San Francisco called Devil's Slide. When I first lived here that was the way we drove but finally it got too dangerous and so there is now a tunnel through the inland hills that skirts the whole area that was failing. They blocked off that section of the old two lane highway and kept it open for walkers and bikes. It was always a part of the drive that you wanted to stop on but there was no shou;der and you didn't dare slow down and look. It was fantastic to be able to leisurely walk along the cliffs and look hundreds of feet down to the water to all these great coves and kelp beds.