There is increasing awareness that the physical environment plays a critical role in young children's cognitive and social development, by offering opportunities for exploration and interaction. In this article a narrative review is presented of 19 studies, published between 1987 and 2017, into the relation between spatial characteristics of the indoor play environment of center-based early childhood care and education settings and children's social and cognitive behavior and development. Studies involved children between six months and six years of age. Several studies reported consistent, interesting outcomes. A layout with an open-zoned arrangement, enabling children to keep eye contact with the caregiver was found to stimulate children to use the space more fully. Designated activity areas for activities such as pretend play and construction elicited different types of social and cognitive behaviors. However, the number of studies is small, and very diverse, both in content and in methodology. Suggestions for future research are discussed. (author abstract)