How do you get the mermaid key on zZelda oracle of ages?

In "The Legend of Zelda: Oracle of Ages," you can obtain the Mermaid Key by first defeating the Boss of the third dungeon, the Mermaid Statue. After defeating the boss, you'll receive the Mermaid Key as a reward. This key allows you to access the areas that are submerged underwater, enabling you to progress further in the game. Be sure to explore the new areas you unlock with it!