This edition of Early Childhood Matters looks at young children’s experiences of growing up in urban settings. A quarter of the world’s children live in poor urban settlements - a fact which presents opportunities to deliver accessible services cost-effectively, but also poses many challenges. The challenges explored in these articles include violence in Venezuela and Mexico, fear of "stranger danger" in Australia, domestic violence and space to play in Rotterdam, involving communities in Peru and Brazil, social structures of the European Roma, and emergency response in Nairobi. The articles feed into an understanding of one of the Bernard van Leer Foundation's programming goals, to improve young children's physical environments - in this case, the various root characteristics of urban  environments that impact the physical and mental development of young children throughout their lives.