Ancient Castle of Ikana

Ikana Castle is the ruling place of Igos du Ikana in The Legend of Zelda: Majora's Mask in the kingdom of Ikana. It is ancient, half destroyed, and sealed shut, but Link accesses it through the bottom of the well. The castle is a mini-dungeon in the game. In the end, Link fights Igos and his elite guard, and after defeating them, learns the Elegy of Emptiness.