Beneath the Well

In Majora's Mask, within Ikana Canyon is a seemingly empty well called the Gibdo Well; however the area Beneath the Well comprises a mini-dungeon which Link must traverse in order to gain the Mirror Shield and be granted entrance to the Ancient Castle of Ikana.

At the bottom of the well is a maze of colossal size, guarded by many traps and enemies. In front of each door within the maze is a Gibdo. In order to advance through the maze, Link must to speak to each Gibdo while wearing the Gibdo Mask and fulfill any need they might have. In each case, this will be a specific item which they will not request directly, but rather give Link a cryptic clue to decipher.

Enemies in the maze include Freezard, Dexihand, Black Boe, Keese, Deku Baba and Wallmaster. A notable enemy within the well is a Poe; however, the only one there must be captured in a bottle and given to one of the Gibdos in order to proceed. At the very end of the maze lies the prize, the Mirror Shield, which grants access to Ikana Castle.

Trivia

 * The sign next to the entrance reads "Entry prohibited due to ghost sightings".
 * This is a unique area in the game because it contains the only regular Fairy Fountain. This requires giving many items to Gidbos and moving along a path that will not bring you to the Mirror Shield.
 * It is heavily hinted that Pamela's Father became a Gibdo after he entered the well.