Since 1985, developers in Downtown San Francisco have been required to build and maintain privately owned public open spaces (POPOS) as a way to ensure more open space in an area that was quickly becoming dense with office buildings. Of course, because building owners don't necessarily want the public "intruding" upon their space (even if it's the law), not all of these secret parks, plazas, terraces, and gardens are easy to find. A lot of times you have to travel through unmarked doors or past security guards to arrive at the hidden oasis.
Regarding that, don't worry. We've got you covered. Last year we wrote about the best of these spaces and exactly what you need to do to get there.
The problem is that now there's a proposal on the table to allow developers to pay into a fund in lieu of building new public spaces. And even worse? If it passes, a bunch of buildings (like the Intercontinental, which has 12,000sqft of public space in the form of two sunny terraces at 888 Howard St) will ask for a retroactive amendment to make their POPOS private in exchange for the fee.