Nivrim.

The Westmark.

A border of the Forest of Region lying on the Westshore of Sirion on the plain Taleth Dirnen in Beleriand. It was under the spell the Girdle of Melian who wanted to honour Ulmo by having some of the waters of Sirion inside the girdle and most of the trees in that wood was old oaktrees. Niwrim ran from Aelin-Uial to Teiglin and was 10-15 Miles wide.