During recent decades, in many cities, important changes in home and neighborhood environments have significantly impacted the play and peer interactions of children. Many urban streets and public spaces have become inhospitable to children. However, parents continue to value outdoor play and access to nature as important to their children’s health and development. Against the background of a re-emerging interest among families and city governments to create child-friendly urban environments, this paper examines social and physical characteristics of such environments, based on research conducted in Amsterdam and Rotterdam, the Netherlands. It concludes that planners and designers need to support the efforts of families to re-claim the street as an important area for urban livability for children.