The northern parts of the Great Water (somewhat conjectural)

A title occasionally given to the ocean beyond the western coasts of Middle-earth, also called the Great Sea or, in Elvish, Belegaer. Though the title is rare, it appears in extremely disparate sources, from the lofty words of the Akallabêth to the mutterings of Gollum. The Great Water was the widest of the oceans of Arda; before the Downfall of Númenor, it extended westwards until it reached Aman. After that time, Aman was taken away and the Earth became 'bent', so that the waves of the Great Sea lapped newly made shores along its western edge.