If you want to escape the city, this is the place to go. Just a short drive from San Francisco lies Steep Ravine campground at the southern end of Stinson Beach. The campsite sits right on the Pacific Ocean and offers some of the best sunsets imaginable. And being so close to SF you'd be surprised at how many stars appear at night. The campsites are set up well, you'd never know other people were nearby. The only sounds you hear at night are some frogs chirping and the waves crashing below.
The campground also has its own beach to explore.