Lair of the Father

thumb|right|Inside the Lair (DS/iOS) Lair of the Father, also known as Cave Bahamut, Cave of Bahamut or Cave of the Phantom God, is a dungeon in Final Fantasy IV and Final Fantasy IV: The After Years. It is the lair of Bahamut, Hallowed Father of the Eidolons.

Final Fantasy IV
The player can visit the cave as soon as they acquire the Lunar Whale and fly to the Red Moon. At three points the path is blocked by a Behemoth in an inescapable set encounter. Once Bahamut is beaten at the end of the dungeon, Rydia can summon him in battle.

The After Years
After Fusoya and Golbez investigate the Impact Crater and fight the Mysterious Girl and Asura, Fusoya grows concerned for Bahamut's fate with the girl's power to control Eidolons. The two enter the Lair of the Father to check on him, and find him petrified. Similar to Final Fantasy IV and its Behemoths, Count Malboro block the path at points.

Eidolon Search Sidequest
In the iOS version of Final Fantasy IV, the player can embark on a quest to find eidolons scattered around the world. The seventh eidolon is found near Bahamut's hall in Lair of the Father, on the right side before the stairs. He asks Rydia if she is paying her respects, then the eidolon returns.

Final Fantasy IV

 * Genji Shield
 * Genji Helmet
 * Genji Armor
 * Genji Gloves

The After Years

 * Aura Staff
 * Dry Ether
 * Ether
 * Ice Shield

DS formations

 * Behemoth x1
 * Dark Sage x1
 * Dark Sage x3
 * Dinozombie
 * Gold Dragon, Silver Dragon
 * Armored Fiend x1
 * Armored Fiend x2
 * Moonmaiden x2, Dark Sage x1
 * Moonmaiden x1, Dark Sage x1
 * Bone Dragon x1

Music
The Lair of the Father shares the background music of the Feymarch, "Town of Illusions".