This Danish study investigates the relationship between children in preschool (age range 3-6.5 years) and the outdoor environments they use. The main aim is to describe and analyse the outdoor features of significance for children’s activities and of importance for design and management of green settings for preschools. The intent is to facilitate transfer of knowledge from preschools to planners and managers of green settings such as woodland, parks, green lots and playgrounds. The central concept applied is that of affordances, here defined as the meaningful action possibilities of the environment. The study is mainly inspired by ethnographic methods. The results include a classification of outdoor features adjusted for children in preschool that may be used to get an overview of features and possible improvements in a setting. Additionally there are considerations about the difference between forest features and manufactured features, a detailed account of the affordances of ditches, and a description of the forest sites used by a Danish forest preschool. Children were attracted to features with changing and not fully explored action possibilities; forest features added variation, gradation and change resulting in successively new affordances.