If you take that costal road South, (the one that runs in front of the zoo and then the Skyline exit, you will come to a place called Fort Funston. It used to be an old missle base. It's current attraction is that it sits on top of a cliff, hundreds of feet above the beach and is a local, favorite hang gliding site. When the wind is onshore, flyers can, literally, step off the cliff edge and they get instant lift. Hang gliders can drift back and forth, along the cliff edge and, in some cases, can actually hover, within a few yards of spectators. There is even nice viewing platform set up, just a few feet away from the launching ramp. It is possible for spectators to actually have conversations with the flyers as they drift by.
Be sure to bring your camera.