??? is the name of a bonus dungeon in the Maxima version of World of Final Fantasy that is unlocked after defeating the final boss. It is accessed by entering a purple portal that appears on the first floor of The Crystal Tower. The player is notified of this portal from the Tip Jar when the player loads their save file.
The dungeon consists of only one room and resembles the illusionary version of the Crystal Tower's Gate room. A message inscribed on the tombstone tells the player of encountering the "Immortal Dark Dragon" by "breaking the seals of the six lands" and "searching the skies" to do so. This hints to the player having to use the airship to traverse to six different unmarked locations on the overworld to activate Puzzle Switches:
Once the player meets this criteria and returns to this location, the Immortal Dark Dragon appears in front of the tombstone where the player can challenge him to battle.
|Initial Haste Mirajewel||Defeat The Immortal Dark Dragon.|
- Reward items
The following items can be obtained each time the player defeats The Immortal Dark Dragon.
|Name||HP||Elemental Resistances||Ailment Resistances||Imprism|
|The Immortal Dark Dragon||~104,024||0||0||0||0||0||0||0||0||100||100||100||100||100||100||100||100||Unimprismable|
|The Immortal Dark Dragon (replica)||8,760||0||0||0||0||0||0||0||0||30||30||30||30||30||30||30||30||Unimprismable|
|The Immortal Dark Dragon (Superboss)||—|
"Serious Melody" is the background theme that plays in this dungeon.