Answer :
For the boys The rockpile is a forbidden place beyond their parents control. It is this forbidden nature of the rockpile that attracts the boys. For the parents the rockpile is a place of danger where they cant protect their kids. In the whole story the Rockpile symbolizes the dangers of the streets in harlem, parents try to keep the kids away from it by keeping them home, but its hard for them to keep occupied. Hope this helps:)