Free, preregistration suggested. Build with sticks, crawl through logs, run on hills, create with natural materials like rocks, pinecones, leaves, and mud. This event will run rain or shine—we will move indoors if weather doesn’t permit to be outside. In order to receive free parking, registration is required prior to attending. Chicago Botanic Garden Members do not need to register. Offered in partnership with The Alliance for Early Childhood as part of the Let's Play! Ongoing Community Program.