On our playground, Waipao, we have a big covered fenced in sand area.  Sand experiences have a sensory motor quality, which is a unique attribute that allows children to release tension in a non-threatening environment.  It allows children to have hands-on experiences using four of their senses (touch, sight, hearing, and seeing).  In addition, it promotes positive social interactions.  When asked by teacher, “What are you doing?”  One group was making a castle.  Another group was making food.  And the last group made a volcano.