Citadel of the Ocean

"This Citadel, which the will of the gods have caused to appear, is a place that the gods of the ancient world prepared so that they might test the courage of men. Only one who is able to overcome the trials that await here will be acknowledged as a true hero. Only then will that hero be permitted to wield the power to destroy the great evil."

Story
When Isling was flooded with the Darkfallen, the gods created the tower to test the courage of anyone who wished to wield the Trident, and to prevent unworthy people from obtaining it. To gain access to the tower, Katelynn collects the four Chronograph Fragments and sets them in the hands of the Maiden of the Sea mural.

Once all four fragments have been placed in the murals' hands, they break apart and a beam of light shines out to the ocean. The Citadel of the Ocean then rises up from beneath the sea. The area in which the tower is located is empty until this happens.

Katelynn deciphers the puzzles and defeats the enemies of the tower, before being presented with the gods' final challenge, the Tower's boss: The Doppelgänger. Upon defeating the boss, Katelynn is transported to the very top of the Citadel, where he rings the Citadel's bell. This opens a portal to the room where the Trident is located.

Dungeon
The main tower is tall, cylindrical and made of white-gray stone. Strange black patterns cover small parts of the surface. There are a few windows at the top of the tower.

The lowest level of the Tower has no floor, and is filled by water flowing in from the sea outside. Katelynn must traverse most of the area while swimming.

The main objective of the dungeon is to find the three Servants of the Tower and guide them back to a central chamber to activate a lift warp to the top floor. These statues can be lifted by Katelynn, or can follow her when she calls them. The statues are crucial to the dungeon's puzzles. Katelynn also fights a Water Construct for the Mythic Az within the tower.

Once the lift warp is activated, Katelynn can go up to the third floor, retrieve the Main Citadel Key, and set off on the final path to the boss. This path is, unlike the rest of the dungeon, on the outside of the tower and the Isling Ocean is visible far below. Katelynn must fight past Wyverns and Condors without falling from the ledge to arrive at the gods' final test, the Doppelgänger.