From Zelda Wiki.org
Location of the legendary Waterfall of Wishing
In
A Link to the Past, a large waterfall known as the
Waterfall of Wishing can be found at the northeastern corner of
Lake Hylia, partway between the
Magic Shop and
Zora River. By swimming up the center of the waterfall, Link can access a secret which contains a small pond. In the game, walking up to this pond asks if you want to throw something in. Any item the player throws in will be returned by a human-sized
Fairy dwelling within the pond, but three certain items will be different upon return if you answer the Fairy's questions honestly:
