Children's play area (7)
I believe the answer is:
sandpit
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">children's play area</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sandpit that I've seen before include "Play area for small children" , "children may play here" , "Excavation for children to play in" , "area for kids to play in" , "place where youngsters can play" .)