I remember loving to roll down a grassy hill when I was young. Did you do this?
Another thing we use to love, which combined outdoors and laughter, was spinning around and around and then falling down flat on our back with eyes wide open to watch the world go spinning around. Going on the tire swing was also great fun. All these activities are loved by most children and stimulate the vestibular system which is the balance centre in the inner ear. As a matter of fact it is immature in infants and young children and they need these activities. Luckily they are fun and come naturally for most. Some children however do not enjoy these activities and should not be forced to participate.
More on this vestibular stimulation soon.