creativity by children, which helped the idea spread worldwide. Playgrounds in the Soviet Union Playgrounds were an integral part of urban culture in the USSR. In the 1970s and 1980s, there were playgrounds in almost every park in many Soviet cities. Playground apparatus was reasonably standard all over the country; most of them consisted of metallic bars with relatively few wooden parts, and were manufactured in state-owned factories. Some of the most common constructions were the carousel, sphere, seesaw, rocket, bridge, etc. Design Playground design is influenced by the intended purpose and audience. Separate play areas might be offered to accommodate very young children. Single, large, open parks tend to not to be used by older schoolgirls or less aggressive children, because there is little opportunity for them to escape more aggressive children. By contrast, a park that offers multiple play areas is used equally by boys and girls. Effects on child development Professionals recognize that the social skills that children develop on the playground often become lifelong skill sets that are carried forward into their adulthood. Independent research concludes that playgrounds are among the most important environments for children outside the home. Most forms of play are essential for healthy development, but free, spontaneous play—the kind that occurs on playgrounds—is the most beneficial type of play. Exciting, engaging and challenging playground equipment is important to keep children happy while still developing their learning abilities. These should be developed in order to suit different groups of children for different stages of learning, such as specialist playground equipment for nursery & pre-school children teaching them basic numeracy & vocabulary, to building a child's creativity and imagination with role play panels or puzzles. There is a general consensus that physical activity reduces the risk of psychological problems in children and fosters their self-esteem. The American Chief Medical Officer's report (Department of Health, 2004), stated that a review of available research suggests that the health benefits of physical activity in children are predominantly seen in the amelioration of risk factors for disease, avoidance of weight gain, achieving a peak bone mass and mental well-being. Exercise programmes "may have short term beneficial effects on self esteem in children and adolescents" although high-quality trials are lacking. Commentators argue that the quality of a child's exercise experience can affect their self-esteem. Ajzen TPB (1991) promotes the notion that children's self-esteem is enhanced through the encouragement of