The Great Vortex, or the Vortex of Canaan, is a mysterious, eternally spinning vortex located on the ocean west of the Eresian Continent and the setting for Ys VI: The Ark of Napishtim. A vortex of mysterious origins, and said to have a treasure within its center, it piqued the interest of treasure-seeking pirates such as the famous pirate king Ladoc. The term Great Vortex is used by the people outside of the storm who are ignorant of what's inside.
Within the vortex lies the Canaan Islands that has lost contact with the outside world. It's natural inhabitants, the Rehda Tribe, are said to have dwell on the islands since ancient times. They referred to the vortex by the name of their land Canaan. Aside from the Rehda Tribe, there are also humans that have been wash ashore by shipwrecks as explained by Olha.
It was revealed the Ark of Napishtim was responsible for the appearance of the vortex which circumscribed Zemeth Island where the artifact was buried.