Cûm Taran (Du. "Vale of thunder") ,so named because its great elevation frequently brought thunder clouds near to the earth, formed part of the highland plateau at the center of the Belfalas peninsula, enclosed by the two great arms of the Ered Torthonion. Divided from the larger Nan Roechbin by a secondary mountain ridge, Cûm Taran served as the sacred ground and barrow field for the five Daen clans of the Ered Torthonion that remained true to the Dúnedain during the War of the Last Alliance, and so escaped the curse of the Oathbreakers.