Public nudity is legal in San Francisco. Sometimes people will see naked people walking down the street in San Francisco. As someone who promotes chastity I support public nudity because the main thing that encourages sexual arousal is not the naked body itself but rather the interplay between concealment and revealing of the body. When people are naked the body loses its allure because people get used to seeing it.
Here are some links to information on nudism in San Francisco, some of the links may be homosexual oriented however in posting these links this is not an endorsement of homosexuality. I am homophobic.
Another aspect to public nudity that is good is the fact that exposure to sunlight allows the body to generate vitamin D. Too much sunlight is bad, it can cause heat stroke and sunburn. However moderate exposure to sunlight in weather that is not too hot is healthy. If one is going to wear sunscreen I recommend that one exercise caution because sunscreen has been shown to cause skin cancer.
I am not going to post any videos of public nudity in San Francisco because some people might find such videos offensive however there are many videos on that one can access by searching youtube.