A public space is not public by virtue of it not being private. What makes it public is that the public seeks it out as a place to be. People occupy it instinctively because it facilitates social and other activities. Transforming mere space into public space may be a science, and it may be an art. It is certainly common sense.
The conventional way to use a space is to build something like a park. But without some kind of an attraction to draw people to use the park, it would simply be a piece of land dotted with trees.
In order for a space to reach its full potential, there needs to be something that sustains the space, for example some kind of community involvement to get people to go there and take advantage of the space.
