Children's well-being in early childhood education and care (ECEC) is associated with their participation in both planning and assessing ECEC activities. The aim of the study presented here was therefore to explore children's experiences of participating in different physical environments and activities in ECEC institutions. Quantitative data were collected from structured conversations with 3693 4-6-year-old children using the Norwegian ECEC Well-Being Monitor from 2014 to 2019. Among the results, children's experiences of participating in ECEC activities were diverse and depended upon the physical environment, although most children experienced higher degrees of participation when outdoors instead of indoors. Furthermore, going hiking and circle time are activities the majority of children have to attend, even if they do not want to. Increased awareness about how children experience opportunities for participating in ECEC activities is important for ECEC institutions and may influence pedagogical thinking and planning in different environments and activities.