??? is the name of a location in the Maxima version of World of Final Fantasy, located on the "Besaid" continent in Grymoire. It is one of six unmarked locations on the world map that can only be reached by airship, accessible after reading a message inscribed on the tombstone at the mysterious location within The Crystal Tower. On the world map, its location is situated near the pin that represents The Sunken Temple.
The location consists of only one room and resembles the Secret Quacheon of The Sunken Temple. At the end of the room is a Puzzle Switch that must be activated to break a seal required to encounter The Immortal Dark Dragon back at the mysterious location. The Puzzle Switch is referred to as the Water Seal and requires a stack with the combined weight stat of 14 of higher, and Water elemental resistance of 150 or higher to activate it.