Communities are focusing more on the needs of children, youth and families, and global policies now recognize the rights of young people to have a healthy environment in which to live, play and work. A significant body of research which supports child-friendly cities has been oriented to designing public spaces, improving independent mobility, enhancing access to the natural environment, and providing opportunities for life chances more generally. For example, a key area of importance is safety and well-designed walking and cycle paths that effectively and efficiently connect residential areas to parks, public spaces, schools, and community amenities. Access to nature and the opportunities to play safely outside are other critical areas of research that provide evidence for improving environments for young people. Drawing on examples of child-friendly environments, this chapter identifies the key features of places that can have a positive impact on growing up – and how explicitly engaging with evidence-based theory facilitates the design of great places, particularly for young people.