Hero's Key

The Hero's Key is a quest item from The Legend of Zelda: Four Swords. Link needs three of these keys in order to access Vaati's Palace; however, he will only be able to obtain these keys after playing through the game once, obtaining three Golden Keys, and defeating Vaati.

After defeating the boss of the Sea of Trees, Talus Cave, and Death Mountain, Link will meet a Great Fairy. If he has collected over 5000 Rupees in the stage, the Great Fairy will award him with a Hero's Key.

After defeating Vaati for the third time by means of the Hero's Keys, the game is complete.