The Great Sea Trench is a location in Final Fantasy V from Galuf's world, accessible only in the merged world. It is a volcanic underwater cave and the location of one of the tablets needed to unseal the twelve legendary weapons in the Sealed Castle, as well as of the "great Dwarven Kingdom", where five dwarves live.
Because the Great Sea Trench is mentioned in the Sealed Tome as a holding place for a tablet, it can be presumed that it predates the world being split, which would make it over a thousand years old when visited in Final Fantasy V. The history of the dwarves is unknown, although only five were met by the time of Final Fantasy V, who did not pay attention to the affairs aboveground (which they referred to as "Above Ground-lali").
In Final Fantasy V, after obtaining the submarine at the Catapult, the Light Warriors headed into the Great Sea Trench. At the bottom, they found their third tablet, but three of Exdeath's demons attacked them: Triton, Nereid, and Phobos. After defeating them, the Light Warriors obtained the tablet as well as the ultimate time magic, Meteor.
The Great Sea Trench is located beneath a crack on the ocean floor, making it only reachable via submarine. As gargoyles block the entrance, it cannot be entered without the Sealed Tome.
The Great Sea Trench is a vast, mostly volcanic cave. Many floors are filled with lava, with only a small patch of water near the dwarves. The dwarves have a tiny society, though one of the five dwarves runs a weapon and armor shop, suggesting they are blacksmiths.
Shops can be seen when reaching the dwarves.
- Weapon Shop
|Gaia Hammer||12,800 gil|
|Morning Star||7,800 gil|
|Rune Bow||10,000 gil|
- Unknown (#168)
- Unknown (#169)
- Unknown (#170)
- Unknown (#171)
- Unknown (#172)
- Triton (Boss)
- Nereid (Boss)
- Phobos (Boss)
The random encounters in this dungeon are undead. An easy way to get through is to use the Bard's Sing ability to continuously cast Requiem to deal several thousand points of damage to monsters for no MP. A Geomancer is also a useful addition to the party as not to take damage from the lava floors while traveling.
The background theme that plays at the Great Sea Trench is called "Beyond the Great Blue Seas".