Abstract Although school grounds have long been recognised as effective settings for children's physical activity, the design of current school grounds in Australia does not often meet children's preferences for physical play. This participatory qualitative study explored the sophisticated layers of unofficial environmental opportunity that children discovered to support their physical play activities in school grounds. This paper focuses particularly on the activities linked with unofficial paths – the paths that have not been designed deliberately to facilitate movement patterns but are perceived and utilised by children throughout the school grounds. Three methods were used (walking tours, focus groups and behaviour mapping) in three Australian public primary schools. The results from the thematic analysis showed that children's choice of unofficial paths was associated with the form of these paths, their affordances, the ground surface materials and the network of their connections. The study also identified the link between children's choice of these paths and two considerations: the school rules; and their perception of overcrowding. The discussion indicates that the overlay of unofficial paths within school grounds adds more layers of diverse environmental and social opportunities for children's physical play that need to be recognised in school ground design and in school regulations. Understanding children's perception and evaluation of these paths reveals the dynamic relationship between multiple environmental dimensions of paths and children's physical play. This study demonstrates the value of participatory research with children for identifying children's view of child–environment relationships.