Crystal

The Crystals are magical prisons that hold the seven descendants of the Sages in A Link to the Past. The crystals are kept in the dungeons of the Dark World. Princess Zelda herself is held in the seventh crystal. After each of the dungeons, a crystal is received, which frees the maiden in it.

Crystals are also present in Ocarina of Time and Majora's Mask. After completing a dungeon, a Warp appears that turns Link into a crystal and warps him out of the dungeon. Princess Zelda is held captive in a pink crystal in Ganon's Tower at the end of Ocarina of Time.

In Oracle of Seasons, Link find Din imprisoned within a blue crystal before he faces Onox. During the battle, Onox uses the comatose Din to shield himself from Link's attacks. Link can repel the crystal with the Rod of Seasons.

Crystals also appear in Four Swords Adventures, where the maidens are once again held inside them.