My dad would paint tractor tires and we had a sandbox or a swing on a tree. Did that for my daughter too. Made a lid from plywood so cats would not use as a litter box.

Check with your local farmers. We are always looking for tires for our older equipment (hay rakes, wagons) especially 15". Some farmers use tires for erosion issues, weights for hay tarps. We even use them around new trees - heat during winter and holds water in summer (drill holes for drainage/mosquitos).

Track teams can use tires under their high jump and pole vault pits to save wear and tear on the pits and to keep them from sitting in water.

Your picture on this play area above does have a good use for tires. However did they think of the possibility of harboring mosquitos in the open area that can fill up with water??

I've always wanted a tire swing.