The skateboard park

This could almost come from Raheny's "Cheap occupations for low maintenance kids" series.

Another way of keeping the kids entertained in recessionary times.

The cost in this case is zero.

Unless they decide that they do actually want skateboards in which case it could cost a small fortune but I think they prefer their imaginations.

This went on for a very long time. Until I could hardly walk for laughing and they were dripping with sweat and panting like pit bulls. They all made it to the top. Eventually.