The Silmarillion

Thus the realm of Finrod was the greatest by far, though he was the youngest of the great lords of the Noldor, Fingolfin, Fingon, and Maedhros, and Finrod Felagund. But Fingolfin was held overlord of all the Noldor, and Fingon after him, though their own realm was but the northern land of Hithlum; yet their people were the most hardy and valiant, most feared by the Orcs and most hated by Morgoth.

Upon the left hand of Sirion lay East Beleriand, at its widest a hundred leagues from Sirion to Gelion and the borders of Ossiriand; and first, between Sirion and Mindeb, lay the empty land of Dimbar under the peaks of the Crissaegrim, abode of eagles. Between Mindeb and the upper waters of Esgalduin lay the no-land of Nan Dungortheb; and that region was filled with fear, for upon its one side the power of Melian fenced the north march of Doriath, but upon the other side the sheer precipices of Ered Gorgoroth, Mountains of Terror, fell down from high Dorthonion. Thither, as was earlier told, Ungoliant had fled from the whips of the Balrogs, and there she dwelt a while, filling the ravines with her deadly gloom, and there still, when she had passed away, her foul offspring lurked and wove their evil nets; and the thin waters that spilled from Ered Gorgoroth were defiled, and perilous to drink, for the hearts of those that tasted them were filled with shadows of madness and despair. All living things else shu

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 cha

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 dwelt after the great defeat. But south of the Andram, between Sirion and Gelion, was a wild land of tangled forest in which no folk went, save here and there a few Dark Elves wandering; Taur-im-Duinath it was named, the Forest between the Rivers.

Gelion was a great river; and he rose in two sources and had at first two branches; Little Gelion that came from the Hill of Himring, and Greater Gelion that came from Mount Rerir. From the meeting of his arms he flowed south for forty leagues before he found his tributaries; and before he found the sea he was twice as long as Sirion, though less wide and full, for more rain fell in Hithlum and Dorthonion, whence Sirion drew his waters, than in the east. From Ered Luin flowed the six tributaries of Gelion: Ascar (that was after named Rathlóriel), Thalos, Legolin, Brilthor, Duilwen, and Adurant, swift and turbulent streams, falling steeply from the mountains; and between Ascar in the north and Adurant in the south, and between Gelion and Ered Luin, lay the far green country of Ossiriand, the Land of Seven Rivers. Now at a point nearly midway in its course the stream of Adurant divided and then joined again; and the island that its waters enclosed was named Tol Galen, the Green Isle. There Beren and Lúthien dwelt after their return.

In Ossiriand dwelt the Green-elves, in the protection of their rivers; for after Sirion Ulmo loved Gelion above all the waters of the western world. The woodcraft of the Elves of Ossiriand was such that a stranger might pass through their land from end to end and see none of them. They were clad in green in spring and summer, and the sound of their singing could be heard even across the waters of Gelion; wherefore the Noldor named that country Lindon, the land of music, and the mountains beyond they named Ered Lindon, for they first saw them from Ossiriand.

East of Dorthonion the marches of Beleriand were most open to attack, and only hills of no great height guarded the vale of Gelion from the north. In that region, upon the March of Maedhros and in the lands behind, dwelt the sons of Fëanor with many people; and their riders passed often over the vast northern plain, Lothla