Many years ago I made it to San Francisco on a trip. It is an amazing city in terms of stunning architecture, giant bridges, interesting cultural areas and very original scenes. The geography and topography are unlike any other major city in North America.
San Francisco has very big hills throughout its whole area. This creates very steep streets. Driving down these streets is nerve-wracking when one is not used to them. You come to a cross street and you cannot see the street below. It is like you are approaching a cliff.
One of the effects of these steep streets is that the sidewalks get very hard to walk up. So certain streets consist not of sidewalks, but steps. It was absolutely amazing to see these steps that only the physically fit could, or should tackle. And that an intoxicated person should avoid at all costs.