The Spanish architect Manuel de Sola-Morales once suggested in the pages of OASE that the civic and morphological richness of cities rests in collective spaces that are neither strictly public nor strictly private--public spaces used for private activities, private spaces that allow for collective use, and a whole spectrum in between. In recent years the design of these hybrid spaces has become a common intervention in the contemporary city. At the intersection between architecture and planning, the restricted and the shared, these buildings and projects blend private and public life. OASE 71 focuses on their definition, their character and the roles they play. How are public and collective domains expressed, related and incorporated within a building and in the relationship between building and city? As landmarks and microcosms of the urban condition, how do those relationships define their cities?