I just remembered one of the things we called our outdoor play area in elementary school (in Maryland). The part that was paved was called the "blacktop". I think the rest of it wasn't called anything, except for the part that had the playground equipment, and that part was called by whatever part of it was being referred to (the swings, the monkey bars, the slide, etc.). We might have referred to the softball diamond as something, but I can't remember. Probably the "backstop". In Rhode Island, I don't remember it being called anything except "outside" or "outdoors" or something like that. There was no equipment in my elementary school in RI. Just paved area and grassy area, which included a softball diamond.