There Mount Rerir, and about it many lesser heights, stood out from the main range of Ered Lindon westward; and in the angle between Rerir and Ered Lindon there was a lake, shadowed by mountains on all sides save the south. That was Lake Helevorn, deep and dark, and beside it Caranthir had his abode;
- The Silmarillion, Chapter 13
Lake Helevorn lies at the foot of Mount Rerir.