Carved into a gargantuan reef, the fortress was made up of four rocky towers covered in barnacles and coral. Between these towers sat a large sinkhole descending into the heart of the fortress. A natural phenomenon sometimes caused the ocean currents to form a great whirlpool with enough strength to draw ships down into the bottom of the sinkhole.
The interior of the fortress was made up of air-filled chambers and corridors. Sized to gigantic standards, ceilings in the fortress were 50 feet high. Oval windows made of thick, transparent crystal lined many rooms. The storm giants of the Maelstrom cultivated giant anemones used for storage and waste disposal. Continual flames illuminated wall sconces around the fortress.