Hard as it is to believe, playground safety has only really existed as a concept since the early 1980s. In 1981, just as Leathers’ playgrounds were flourishing, a spate of highly publicized playground injuries prompted the first playground safety guidelines from the U.S. Consumer Safety Commission. Throughout the 80s, fear of accidents snowballed, as more and more parents sued cities and states for their children’s injuries. A few crusaders, including consumer advocate Theodora Briggs Sweeney, turned up the pressure on playground designers, local governments and manufacturers to create safer playground equipment. Many parks removed materials and structures considered dangerous, including anything that could entangle a child and installed softer surfaces, replacing concrete with rubber or wood chips.

A large body of research has proven that children today are given less freedom by their parents than previous generations. In 1972, geographer Roger Hart conducted a famous study, measuring the distances that children in a small New England town traveled outside their homes, producing maps that showed the average distance most children were allowed to stray, and how far they actually went. When he returned to the same town in 2004 and caught up with the now-grown children he’d studied to see how they were raising their own kids, he found his experiment impossible to repeat: the parents barely trusted their children to go outside their sight, not to mention to be followed on unsupervised adventures around the town.

A backlash to the phenomenon of “helicopter parents” and “overprotected children” (as journalist Hanna Rosin calls them) has taken shape over the last few years, resulting in the concept of “free range” kids, who are given a longer leash by their parents, coming into vogue as a child rearing practice. Some parents today are leaning towards allowing their children experiences that more closely resemble the unsupervised freedom they had while growing up.

One of the more radical results of this movement has been the resurrection of “adventure playgrounds”, a largely lost tradition started in post-World War II England.

Adventure playgrounds resemble junk yards in which kids have near total freedom and are given permission to take risks that would give most 21st century parents a heart attack. They light fires, use real tools like saws and hammers, climb trees and play in the mud. Adventure playgrounds employ “playworkers”, who are highly trained to supervise children from a distance, encouraging them to take measured risks and learn from the consequences.

Filmmaker Erin Davis is the creator of a short documentary about a UK adventure playground called The Land. Watching the film, which features scenes of children lighting fires with wet cardboard and engaging in other precarious behavior, is simultaneously nostalgic, heartwarming, and nerve wracking.

Davis believes that spaces like adventure playgrounds teach children valuable skills about risk which are essential for decision making. “They look around and at The Land and they get it,” she told me. “They don’t think ‘I can jump off a tree.’ They move their bodies differently in that space, and that awareness is valuable.”

“If [an adult] says ‘don’t climb that’ a child is going to be like ‘ok, I won’t’, but if they develop for themselves an idea of their personal boundaries and limitations, that’s a really important place to be psychologically by the time you’re a teenager and you’re making even higher stakes decisions about your personal safety,” Davis explains. “What’s happening at the heart of The Land, and can happen in any play environment if we let it, is that children are in control of the content and the direction of their own play.”

Not everyone sees the advent of greater parental and governmental involvement in play negatively. National Recreation and Parks Association playground safety expert Caroline Smith doesn’t see the last few decades of playground safety regulations as increasingly stringent, but as a natural progression adapting to the information on injuries and accidents that has become available over time. “We had the reporting, so [regulators] were able to identify where injuries were occurring. [The regulations] have just gotten more specific,” she says.