When Ar-PharazĂ´n dared to go against the Ban of the Valar, and stepped foot on the forbidden shores of Aman, he and his men were placed in the Caves of the Forgotten and there they were doomed to remain until the Last Battle and the Day of Doom when Arda would cease to exist in the same form.
Encyclopedia entry originally written by Nienna-of-the-Valar