The Silmarillion - J. R. R. Tolkien [73]
Southward lay the guarded woods of Doriath, abode of Thingol the Hidden King, into whose realm none passed save by his will. Its northern and lesser part, the Forest of Neldoreth, was bounded east and south by the dark river Esgalduin, which bent westward in the midst of the land; and between Aros and Esgalduin lay the denser and greater woods of Region. Upon the southern bank of Esgalduin, where it turned westward towards Sirion, were the Caves of Menegroth; and all Doriath lay east of Sirion save for a narrow region of woodland between the meeting of Teiglin and Sirion and the Meres of Twilight. By the people of Doriath this wood was called Nivrim, the West March; great oak-trees grew there, and it also was encompassed within the Girdle of Melian, that so some portion of Sirion which she loved in reverence of Ulmo should be wholly under the power of Thingol.
In the south-west of Doriath, where Aros flowed into Sirion, lay great pools and marshes on either side of the river, which halted there in his course and strayed in many channels. That region was named Aelin-uial, the Twilight Meres, for they were wrapped in mists, and the enchantment of Doriath lay over them. Now all the northern part of Beleriand sloped southward to this point and then for a while was plain, and the flood of Sirion was stayed. But south of Aelin-uial the land fell suddenly and steeply; and all the lower fields of Sirion were divided from the upper fields by this fall, which to one looking from the south northward appeared as an endless chain of hills running from Eglarest beyond Narog in the west to Amon Ereb in the east, within far sight of Gelion. Narog came through these hills in a deep gorge, and flowed over rapids but had no fall, and on its western bank the land rose into the great wooded highlands of Tauren-Faroth. On the west side of this gorge, where the short and foaming stream Ringwil tumbled headlong into Narog from the High Faroth, Finrod established Nargothrond. But some twenty-five leagues east of the gorge of Nargothrond Sirion fell from the north in a mighty fall below the Meres, and then he plunged suddenly underground into great tunnels that the weight of his falling waters delved; and he issued again three leagues southward with great noise and smoke through rocky arches at the foot of the hills which were called the Gates of Sirion.
This dividing fall was named Andram, the Long Wall, from Nargothrond to Ramdal, the Wall’s End, in East Beleriand. But in the east it became ever less sheer, for the vale of Gelion sloped steadily southward, and Gelion had neither fall nor rapids throughout his course, but was ever swifter than was Sirion. Between Ramdal and Gelion there stood a single hill of great extent and gentle slopes, but seeming mightier than it was, for it stood alone; and that hill was named Amon Ereb. Upon Amon Ereb died Denethor, lord of the Nandor that dwelt in Ossiriand, who marched to the aid of Thingol against Morgoth in those days when the Orcs first came down in force, and broke the starlit peace of Beleriand; and upon that hill Maedhros