Possible Clues:

• Backyard play area
• Playground feature
• Where a kid might build a castle ... or when parsed differently, a hint to the starred clues' answers
• Place to build a castle
• Children ultimately in pathetic fight for play area
• Make smooth punch? It's full of grains!
• Where little kids dream of stardom
• Place to play
• Playground section, sometimes
• Castle location, maybe