Altar of the Demon King

In Spirit Tracks, the Altar of the Demon King is an ornate altar located within the topmost chamber of the Tower of Spirits that overlooks the entire land of Hyrule. The altar bears the new symbol of the kingdom of Hyrule which also serves as a symbol of the Spirits of Good, who imprisoned the Demon King's spirit within the altar itself. To reach the chamber that houses the altar, one must climb all of the floors of the tower and reach a chamber of stained glass that leads out onto a catwalk that surrounds the tower and circles it as it rises to the topmost chamber that houses the altar, the chamber being outdoors but at the very top of the tower.

After restoring the fragmented Tower of Spirits to its original state, Link and Princess Zelda's spirit journey to the top of the tower hoping to reach the altar chamber at the top before Cole and Byrne can succeed in freeing Malladus's spirit from the altar by completely possessing Princess Zelda's body. After fighting their way through all of the challenging floors of the tower, the pair arrive in the chamber of stained glass just beneath the altar chamber and are forced to face Byrne in battle. Though they ultimately succeed in besting Byrne in battle, the villain escapes through the doorway leading out onto the catwalk that leads to the altar chamber. Cole successfully utilizes the altar to fuse Malladus's weakened spirit into the vacant body of Princess Zelda just as Link and the princess's spirit reach the chamber. After knocking Byrne out for his foolish demand for power, Malladus escapes in Zelda's body alongside Cole aboard the Demon Train, which rides past the tower and transports the two villains to the Dark Realm to await the time when Malladus will have full control of Zelda's body.

Link later returns to the chamber while on a search for the Compass of Light and discovers that the entrance to the topmost floors of the tower is located beneath the altar itself. The altar will rise and yield access to these floors once Link hits the two eye switches adorning the altar with Light Arrows from the Bow of Light.