Minority and low socioeconomic status children are at greater risk for low levels of physical activity and high obesity rates. Designing safe outdoor play environments that support children's physical activity provides a potential mechanism for counteracting childhood obesity. This study examines how the redevelopment of inner-city school playgrounds into Learning Landscapes influences children's physical activity levels, and how neighborhood social processes may influence the success of these playgrounds. Investigators will compare 3 playgrounds that have been redeveloped, 3 that will be redeveloped during the study and 3 that will not be redeveloped during the study timeline to test whether the playground redevelopment leads to an increase in children's physical activity and what aspects of playground design most impact children's physical activity. Children’s physical activity will be assessed using a direct observation method (SOPLAY). A survey will be administered to residents of the neighborhood to assess the role of neighborhood social processes on children's physical activity, and how policies and educational and behavioral programs can encourage children to use the opportunities available in the newly built environment.