The Sunken Cave, also known as Underwater Cave, is an optional dungeon in Final Fantasy III. It is located underwater, beneath the small island to the extreme southeast of the Surface World, so the party will need the Nautilus that can use its feature to dive into the underwater surface. The Sunken Cave has a wealth of chests containing lots of equipment and a few items. At the end, there is a mass of rock and bridge that may hint that there was much more of the cave previously.
There are four chests in a hidden room that are traps. The player must fight the monsters guarding the chests in order to obtain the items inside.
|Tiger Claws||Second Area|
|Dual Tomahawk||Second Area|
|Loki Harp||Third Area|
|Diamond Mail||Third Area|
|Diamond Bracers||Third Area|
|Air Knife||Third Area|
|Phoenix Down||Third Area|
|Diamond Gloves||Third Area|
|Ancient Sword||Third Area|
|Metal Knuckles||Third Area|
|Diamond Shield||Third Area|
|Diamond Helm||Third Area|
|Trident||Hidden room on Third Area. Guarded by Peryton.|
|Aegis Shield||Hidden room on Third Area. Guarded by Zombie Dragon.|
|Reflect Mail||Hidden room on Third Area. Guarded by Death Claw.|
|Triton Hammer||Hidden room on Third Area. Guarded by Eater.|
The background music that plays inside the Sunken Cave is called "Sunken Temple".