In The Silmarillion by J.R.R. Tolkien, the Helcaraxë is an inhospitable region of perpetually shifting pack ice known in the Common tongue as "Grinding Ice" and in Elvish as "Ice Fangs." This region provided the only crossing of the great sea Belegaer that was traversable on foot. Because of this, it was used as an escape route for Morgoth and Ungoliant when fleeing the Valar during the First Age, and it was used again as a path of exodus by Fingolfin to lead his people into Beleriand.

At the end of the First Age, the War of Wrath saw Beleriand sink beneath the great sea, and the Grinding Ice came apart at this time, destroying the only method of transit across the sea other than sailing and flight. The world was sundered and made round (having previously been a single flat, symmetrical continent suspended in space) following the downfall of Numenor in the Second Age, with the sacred Undying Lands rendered permanently inaccessible by mundane means of transit. A polar ice cap reformed at the northernmost region of the planet, but the repositioning of landmasses meant that it was no longer geographically the same location as the previous Grinding Ice. Much of this ice formed atop existing continental shelf rather than over seawater.

The Grinding Ice is not to be confused with Helcar, the enormous pillar lamp placed at the northern end of Arda to provide light for the northern half of the world, prior to the existence of the Two Trees, the sun, and the moon.

Iron Noder 2018, 12/30