from the play time. The enclosed, padded, constrained, low structures prevent the child from taking risks and developing a sense of mastery over his or her environment. Successfully taking a risk is empowering to children. For example, a child climbing to the top of a tall jungle gym feels happy about successfully managing the challenging climb to the top, and he experiences the thrill of being in a precarious, high position. By contrast, the child on a low piece of equipment, designed to reduce the incidence of injuries from falls, experiences no such thrill, sense of mastery, or accomplishment. Additionally, a lack of experience with heights as a child is associated with increased acrophobia (fear of heights) in adults. The appearance of safety encourages unreasonable risk-taking in children, who might take more reasonable risks if they correctly understood that it is possible to break a bone on the soft surfaces under most modern equipment. Finally, the playground that is designed to appear low-risk is boring, especially to older children. As a result, they tend to seek out alternative play areas, which may be very unsafe. Risk management is an important life skill, and risk aversion in playgrounds is unhelpful in the long term. Experts studying child development such as Tim Gill have written about the over-protective bias in provision for children, particularly with playgrounds. Instead of a constructed playground, allowing children to play in a natural environment such as open land or a park is sometimes recommended; children gain a better sense of balance playing on uneven ground, and learn to interpret the complexity and signals of nature more effectively. Types Playgrounds can be: Built by collaborative support of corporate and community resources to achieve an immediate and visible improvement to the neighborhood. Public, free of charge, typically found at elementary schools Connected to a business and for customers only, such as those a McDonald's, IKEA, and Chuck E. Cheese's. Commercial enterprises charging an entrance fee, such as Discovery Zone. Non-profit organizations for edutainment as children's museums and science centers, some charge admission, some are free. Inclusive playgrounds Universally designed playgrounds are created to be accessible to all children. There are three primary components to a higher level of inclusive play: physical accessibility; age and developmental appropriateness; and sensory-stimulating activity. Some children with disabilities or developmental differences do not interact with playgrounds in the same way as typical children. A