Some areas of San Francisco are so steep that the sidewalk literally is a stairway; other times it’s just more interesting to have a stairway between streets… or a slide. I once saw a grown man with a briefcase matter-of-factly go down this slide and continue on his way down the hill. Why not?
You have a lot of hills to choose from in San Francisco but in my opinion the best (and most varied) views are from Bernal Hill. Bonus: from my kitchen table I can watch tiny blobs moving around on this hill-- slow blobs are people, fast blobs are dogs.