Children's street culture refers to the cumulative culture created by young children. Collectively, this body of knowledge is passed down from one generation of urban children to the next, and can also be passed between different groups of children (e.g. in the form of crazes, but also in intergenerational mixing). It is most common in children between the ages of seven and twelve. It is strongest in urban working-class industrial districts where children are traditionally free to "play outside" in the streets for long periods without supervision. Difference from mass media culture Children's street culture is invented and largely sustained by children themselves, although it may come to incorporate fragments of media culture and toys in its activities. It is not to be confused with the commercial media-culture produced for children (e.g., comics, television, mass-produced toys, and clothing), although it may overlap. Location and play materials Young children's street culture usually takes place on quiet backstreets and sidewalks, and along routes that venture out into local parks, playgrounds, scrub and wasteland, and to local shops. It can often incorporate many found and scavenged materials such as old car seats, tires, planks, bricks, etc. Sometimes found materials will be combined to create objects (e.g. making guys for Guy Fawkes Night). Play will often incorporate crazes (sometimes incorporating seasonal elements that are freely collected, such as conkers, snowballs, sycamore seeds). It also imposes imaginative status on certain sections of the urban realm (local buildings, street objects, road layouts, etc.). In summer, children may use scavenged materials to create a temporary and semi-hidden "den" or "hideout" or "HQ" in a marginal area near their homes, which serves as an informal meeting and relaxation place. An urban area that looks faceless or neglected to an adult may have deep "spirit of place" meanings in children's street culture. History and research Although it varies from place to place, research shows that it appears to share many commonalities across many cultures. It is a traditional phenomenon that has been closely investigated and documented in the western world during the 20th century by anthropologists and folklorists such as Iona Opie; street photographers such as Roger Mayne, Helen Levitt, David Trainer, Humphrey Spender and Robert Doisneau; urbanists such as Colin Ward and Robin Moore, as well as being described in countless novels of childhood. The research of Robin Moore stresses children's need for 'marginal' unsupervised areas 'within running