Vortex

On the map of Elona:

On the map in the Realm of Torment:

The Vortex is the portal to the Realm of Torment, where the ending of the game takes place. It is also the only way to go to and from the Realm of Torment. The Vortex will lead either to the Gate of Torment or the Mouth of Torment.

When you are near the Vortex in the Mouth of Torment, you suffer the environment effect Approaching the Vortex.