HELCARAXë

In the fiction of J. R. R. Tolkien, 'Helcaraxë', 'Helcaracsë' or the 'Grinding Ice' was an icy waste between the lands of Aman and Middle-earth. Its exact nature is left a little unclear, but it seems to have been broken and shifting pack ice covering the northernmost parts of the Great Sea Belegaer.
Helcaraxë is first recorded as having been crossed by Melkor and Ungoliant after the darkening of the Trees, then later by Fingolfin and his people. One of the victims was Elenwë, wife of Turgon. As a result of the War of Wrath, Beleriand was sundered, and with it 'Helcaraxë' ceased to exist.