nature of the areas in question are intended purely to provide an example and hence in no way limit the sphere of protection of the invention in a particularly preferred way all the various pitches tracks etc 12 18 20 22 illustrated herein or at least one subset thereof are obtained using as base structure a structure of synthetic grass covering of the type illustrated in fig2 this is a structure comprising a sheet substrate 1 with a plurality of filiform formations 2 extending from the substrate 1 so as to simulate the grass blade of natural turf and a particulate filling material or infill 3 dispersed between the filiform formations 2 so as to keep the filiform formations 2 themselves in a substantially upright condition in a particularly preferred way the particulate infill 3 consists of a substantially homogeneous mass of a granular material chosen in the group consisting of polyolefin based materials and vinyl polymer based materials for example of the type described in ep a 1 158 099 in the name of mondo s p a the assignee of the instant application recourse to this structure makes it possible to bestow on the various surfaces 12 18 20 22 biomechanical characteristics differentiated according to the particular specialities that are to be practised on a.