We have a smallish backyard but big enough for kicking a ball around, and also our balcony is huge, so it's really like having a backyard. It's big enough for them to have a trampoline and ride their bikes around. DH is the one home with them after school etc and they do the park usually once a week at least (they walk past it on the way home from school/kindy anyway so hard to say no!!), and on weekends we do the park a lot also. But on days when the park is too wet etc they seem to manage ok here.