Ancient Castle of Ikana

In The Legend of Zelda: Majora's Mask, the Ancient Castle of Ikana is located deep in Ikana Canyon, and is home to the king of the long dead Ikana kingdom.

The castle is an ancient building that is home to countless undead enemies, especially ReDeads and Wallmasters. The upgrade you get in this mini-dungeon is the Mirror Shield. Once you finish the castle you will encounter Igos du Ikana, the ancient king of Ikana, and two of his minions. After using the Mirror Shield to deflect sunlight to Ikana and his dark minions, and beat them, Ikana teaches Link the Elegy of Emptiness to help him reach and complete the Stone Tower.