This guide stems from a research project on children’s den-building culture at one Adventure Playground. Gathering together information from psychology, anthropology and other academic disciplines, this guide provides an accessible and lively exploration of how children’s play building can create a full and rich site culture. With easy suggestions for how to spark children’s building of dens and forts in any play setting and a number of images, this guide is an ideal resource for anyone interested in helping to facilitate children’s free play construction.