Helevorn.

Lake Helevorn. A deep and dark lake, benieth Mount Rerir and shadowed by the mountains of Ered Luin on all sides save the South, in the land Thargelion. Beside the shores of lake Helevorn was the abode of Caranthir and from the lake ran a stream who with one from the Northern side of Mount Rerir became the river Greater Gelion.