The Mermaid Key is a quest item from The Legend of Zelda: Oracle of Ages. This key, shaped like the lower body of a mermaid, opens the door to the Mermaid's Cave, the game's sixth dungeon, but only in the present. The Mermaid Key is given to Link by the first generation of Graceful Gorons as a reward for successfully completing the Goron Dance mini-game for the first time in the past.