This paper looks at young children's creative thinking as inferred through observations of their activities. A total of 52 episodes of child-initiated and adult-initiated activities in 3- to 4-year-olds in an English Children's Centre were analysed using the Analysing Children's Creative Thinking (ACCT) Framework. Results showed that activities such as gardening and construction were as valuable for supporting creative thinking as ones traditionally associated with creativity, for example, music and painting. Outdoor play of all kinds and socio-dramatic play were particularly effective contexts. All adults played a significant role in facilitating children's initial engagement in activities, and at supporting their speculative thinking and use of prior knowledge. Teachers were often more successful than other adults in supporting the acquisition of new knowledge. Child-initiated activities featured the highest levels of involvement, and were associated with trying out and analysing ideas, flexibility and originality, imagining and hypothesising. This was particularly evident in group or pair play. Children were also more persistent in child-initiated activities. Evidence of risk-taking behaviour was low, although more apparent in child-initiated activities than adult-initiated activities, or activities in which adults were present. (Contains 3 tables and 1 figure.)