Secret fort framework for under tree hiding spot. Hula hoops in the garden to a secret fort or to weave through an overgrown area (have edible plants along the way for a sustainable snack for their adventure!
Interesting idea for putting a play area on asphalt, concrete or hard soil in a temporary build. The tires and rocks can be removed, and the sand and rocks swept up. Interesting idea for day cares in urban settings without access to grass or soil.