The Narog was the chief river of West Beleriand, the largest tributary of river Sirion. The Narog began at the Eithel Ivrin in the Ered Wethrin, flowed south and then southeast, flowing through a gorge in a series of rapids where it crossed the hills of the Andram, finally meeting the Sirion in the Nan-tathren, not far above the Mouths of Sirion. Narog's tributaries were the river Ginglith in the north and the river Ringwil in the Taur-en-Faroth.