A shared goal set by many local governments is to stimulate physical activity in neighborhoods. Public playgrounds play an important role in governmental policies for promoting physical activity. Although these playgrounds are generally considered beneficial for participation in physical activity, detailed data on their use is lacking. As a result, it is not clear to policymakers whether their policy choices are the right ones and designers cannot sufficiently align their design choices with the actual behavior of their end users. This Work-in-Progress presents a sensor-based data collection approach to collect detailed data in a real-life setting over a longer period of time. With this, we adapted the Data-Enabled Design process towards public environments by combining a quantitative sensor implementation alongside qualitative research. We show findings from two months of data collection on seven playgrounds and discuss next steps in the Data-Enabled Design framework.