San Francisco architect and Docomomo US/Northern California member, Colin Alley, has written a new essay in which he examines the development of the European adventure-playground movement—this movement being based on children having free access to tools, scrap materials, earth, and controlled risk—within the San Francisco Bay Area from the 1960s up to 1979. The essay, which was published on August 26, 2026, links C. Th. Sørensen's 1943 Emdrup "junk playground" and Lady Allen of Hurtwood's work in the UK to the countercultural design environment of the Bay Area and to UC Berkeley's College of Environmental Design.