Charging to use Parks

Charging in the Royal Parks

This is not just a problem in the Royal Parks. Our school was charged to use Lloyd Park despite the fact the council provided no extra service. The only reason to use the park was to keep some of the students occupied while waiting to visit the William Morris Gallery. The WMG charges but that is fair enough as they provide a guide and escort the students around the Gallery explaining the life of William Morris. Should parks be charging larger groups just to use the park?