Pendant of Wisdom
"Ancient Hylian lore states that only the person who wears the Pendants of Courage, Power and Wisdom can become the Hero. It has also been said that only the Hero can wield the Master Sword. The three Pendants are the key to unlocking the Master Sword from the stone in which it has been embedded for eons. When Link obtains all three Pendants, he should go to the Lost Woods and find the Master Sword. After obtaining the powerful work of art, he can go after the root of the evil."
A Link to the Past
The Pendant of Wisdom is the red-colored and final pendant found at the very top floor of the Death Mountain dungeon, the Tower of Hera, and is acquired by defeating Moldorm. It is required to obtain the Master Sword.
A Link Between Worlds
Tower of Hera Location