Chronicles of Khaldun: Crux of Eternity
The Sea of Howling Souls
The Sea of Howling Souls is a queer border region between the Material Plane and the Elemental Chaos. Sailors appropriately versed in the ways can travel between the realms by accessing the seas outside Flotsam. Of course, as a realm of the Elemental Chaos, it is home to strange creatures and eldritch phenomena, such as the storms of screaming ghosts that give the realm its name.
The Frost Spire is located somewhere in the Sea of Howling Souls.