Creating a wild area for kids

I was thinking of creating a wild play area for kids in the garden (about 5m X 30m); maybe put a climbing frame one end, add some hills and leave it to go wild. I’m wondering however if it will need to be maintained at some stages, cut back etc, to prevent unwanted rodents from making their homes (i.e. so needing tractor access). Is my plan to put play area and wild area together a little naive? I’m imagining Little House on the Prarie with Laura Ingles running through long grass – not an area with rotten grass overrun with rats. Can it be done?