Muir and Stinson Beaches are located off winding, plunging, picturesque Highway 1, just over the Golden Gate Bridge from San Francisco. They are good stops if you have your own vehicle and are also visiting Muir Woods. Please note, though, that the waters are very chilly (high 50s/very low 60s) and somewhat rough, especially to someone like me accustomed to the very warm, tranquil waters of the Gulf of Mexico. I was surprised to find a lack of shells, also—just flotsam and jetsam. I guess I am spoiled by the great shelling of South Padre Island. Swimming or surfing either requires a great constitution or a wetsuit. We had neither, and just wading was painful because of the cold. If you'd like, there is a great lookout point between Muir and Stinson Beaches with a short trail. The location was during WWII the site of an anti-ship gun emplacement. Great photographic opportunities.
Stinson Beach is a very small community between the coastal mountain range and the beach. The beach here is significantly longer and wider than Muir, and we saw many more people here enjoying themselves. I recall in particular a brave? nutty? group of young people wearing regular men's short-type and women's bikini-type bathing suits, "swimming". You could hear their screams from hundreds of feet away as they ran into the chilly surf. Note also that Great White Sharks have been seen in these waters, and attacks are not unknown. Stinson Beach also has a few mom-and-pop-type restaurants and shops. We bought shell jewelry at one of them and paid just $2 each for our necklaces. A great souvenir of a great day.
Please Note: There is no charge to use Muir or Stinson Beaches or to park there; also, those addicted to your cell phones will discover that, due to the mountains, there is no service/signal just prior to entering Muir Woods Park and no service/signal whatsoever on Highway 1 between Muir and Stinson Beaches.