Then it was time to open the picnic basket they had brought with them - lots of lovely sandwiches and cakes and biscuits, with lots of lovely cooling lemonade. It didn't take long to demolish the lot! Much quicker than building their sandcastle!
Sadly, the sandcastle did not last very long after that either because as the tide came in it began to wash away all their hard work, but Bubbles took loads of photographs to remind themselves of it, and they all have the memories of the fun they had building their castle! And they can always go down to the beach another day and build another one!