This chapter reviews the evidence about how teenage boys and girls use parks and other greenspace and the potential health impacts of this. It considers the legal and rights background as potential drivers for change. The chapter examines how change can happen, and in particular why consultation with teenage girls has to be a core part of the process. Boys tend to dominate the space in play areas, often by deliberately excluding girls. Girls themselves report that their use of space is determined and regulated by boys; they avoid areas where boys are present and only go to some spaces when they know they will be empty. Teenage girls recognise the lack of provision of suitable facilities and greenspace – a 2020 survey by Girlguiding showed that 82% of girls felt they should be more involved in designing parks and play areas.