What does the cartwheel zone mean?

Rebecca

A "zone" is a specific area given a designated purpose or set aside for a particular use. So a "cartwheel zone" here refers to a specific area used for the purpose of doing cartwheels, a gymnastic movement which is popular among kids. Ex: The truck pulled into the loading zone to unload products for the store. Ex: This is a bike zone only. No cars or motorbikes allowed.