Both my wife and I grew up on farms, and so we gravitated towards the rural lifestyle. Our children were approaching their teenage years when we finally moved out to the old farm where we still live today.
Now, when they come to visit us, I like to show their children our garden, and the pond and, when we still had them, the chickens. There's nothing quite like the look on a child's face when they meet a baby chick for the first time.
They absorb that sense of accomplishment, and of being part of a team, which comes from sharing a chore with the adults.
The greatest joy for a grandparent is to watch them grow into builders and bird watchers, and to feel that you were a small part of it.
If you want to read a good book about the importance of the outdoors in a child's development, I recommend "Last Child in the Woods" by Richard Louv.