Privately Owned Public Open Spaces, or POPOS, are these little gardens, terraces, plazas, and seating areas that are private property, but are mandated for public use. City planners require developers to add these little “parks” to their buildings to make downtown more pleasant (or even just tolerable). Some are out in the open and used regularly by downtown office workers, and some are hidden away and don’t really serve the community all that well. They pop up in the most densely populated parts of the city, where large public parks are few and far between. Whereas the physical aspect of POPOS are pretty well established by the city planners, the social aspects of what constitutes a “public” space is harder to define. Blaine Merker, from the badass design activist group Rebar, showed superstar producer Stephanie Foo around a few of San Francisco’s POPOS to find out just how public these open spaces really are.