The Wurundjeri Aboriginal story of the Yarra.
One day two boys were playing in the bush, throwing their toy spears at whatever bird they saw. After a while they tired of this game and, sighting an old wattle tree, went up to it in the hope of finding some wattle gum, of which they were very fond. They saw some gum on a bough fairly high up, and one of the boys climbed the tree and reached it. He began to throw the gum down to the other boy, who was waiting for it underneath the tree. But when the lumps of gum reached the ground they disappeared, and the boy who had remained below could not find them. At last he noticed a hole, and thinking that the gum may have rolled down, he poked the end of his little spear in it. As soon as he did this, a deep growling voice was heard and the ground seemed to shake. An old man, who had been sleeping underground with his mouth open, suddenly made his appearance. He picked up the frightened boy and shuffled off, dragging his feet, because he was old and the boy was heavy to carry. As the old man huddled along he made a furrow, which deepened into a gutter, then into a creek, and lastly became the Yarra River. All this time the little boy was crying with fright. At last Bunjil heard him. He put sharp stones in the path of the old man over which he fell, and cut himself into pieces. The boy ran off to his home. Just before the old man died, Bunjil appeared, and said to him "Let this be a lesson to all old men. Thy must be good to little children."
Cache is located in a high muggle environment. Please do not attempt this at lunch time or other peak periods unless you can be super sneaky. Cache should contain a pencil
Credit goes to Combust4 for the original version of this cache.