The Vitr [vitter or veeter] was a caustic sea of chaos on the northern border of Kurald Galain that bordered the Glimmer Fate. It resembled a sea of mercury, that was sometimes calm and mottled in appearance and other times was a raging storm that consumed the land. Air blowing off the sea stung the lungs and anything entering the water was dissolved as if in acid, including solid rock. None knew the source of the Vitr, but some believed it related to the Azathanai. The only thing certain was that the sea was gradually expanding, and the Tiste Wardens of the Outer Reach were determined to keep a watchful eye on it.
In Orb Sceptre Throne
The creature Maker on the Shores of Creation claimed the Vitr was "that from which all creation comes...All that exists. All distills out of the Vitr. And all returns to dissolution. You, I. All life essence. All sentience." The Vitr wiped clean the memories of those who emerged from it and survived. They were as if newly born or newly forged. Then-aj-Ehliel emerged from the Vitr as an amnesiac, and was immune to the caustic properties of the sea as he rescued other castaways like himself.
In Forge of Darkness
While on patrol on the shore of the Vitr, Warden Captain Finarra Stone discovered the partially dissolved corpse of a monstrous Eleint lying half in the sea. Despite missing its head it surged to attack and kill her horse as she approached. Warden Faror Hend found a trail leaving the Vitr and followed it to T'riss, the Azathanai. The corpse of a second, much larger Eleint was later discovered further down the shoreline by a second party of Wardens. When Draconus opened the Gate of Kurald Galain in Kharkanas a second gate momentarily opened over the Vitr sea allowing safe passage to nine Eleint.
Ian C. Esslemont likens the Vitr to the "Greek idea of the eternal flux of chaos and cosmos, of creation and destruction, and the eternal need to renew and you have a force that's constantly eroding and destroying versus a counter-force that's trying to bring order to matter. So it's not void--there is a material there which we call Vitr, and it can be either, it can be unformed and chaotic or it can be made into order, it can be rigidified. And these two forces are constantly at war [at the Shores of Creation]." 
Notes and references
- Gardens of the Moon - Chatting with Steven Erikson, part 1 - As pronounced by Steven Erikson at 1:19:37
- Spoiler Chat: Orb Sceptre Throne with Ian C. Esslemont - A Critical Dragon - As pronounced by Ian C. Esslemont at 47:40
- Forge of Darkness, Chapter 4, UK HC p.83-84
- Orb Sceptre Throne, Chapter 1, US HC p.45
- Orb Sceptre Throne, Chapter 1, US HC p.46
- Forge of Darkness, Chapter 4, UK HC p.87
- Forge of Darkness, Chapter 4, UK HC p.101
- Forge of Darkness, Chapter 7, UK HC p.199
- Forge of Darkness, Chapter 20, UK HC p.654
- Spoiler Chat: Orb Sceptre Throne with Ian C. Esslemont - A Critical Dragon - See 46:45