“There is the birth of the Running River,” said Thorin. “From here it hastens to the Gate. Let us follow it!”
Out of a dark opening in a wall of rock there issued a boiling water, and it flowed swirling in a narrow channel, carved and made straight and deep by the cunning of ancient hands. – The Hobbit, Chapter XIII Not At Home
“But beyond, in the great fief of Belfalas, dwelt Prince Imrahil in his castle of Dol Amroth by the sea, and he was of high blood, and his folk also, tall men and proud with sea-grey eyes.” – Lord of the Rings. Vol 3: The Return Of The King, Book 5: The War Of The Ring, Chapter 1: Minas Tirith.
Through long ages the Valar dwelt in bliss in the light of the Trees beyond the Mountains of Aman, but all Middle-earth lay in a twilight under the stars. While the Lamps had shone, growth began there which now was checked, because all was again dark. But already the oldest living things had arisen: in the seas the great weeds, and on earth the shadow of great trees; and in the valleys of the night-clad hills there were dark creatures old and strong. – The Simarillion, Quenta Silmarillion, Chapter III Of the Coming of the Elves and the Captivity of Melkor
Therefore he opened his heart to Thingol, telling him of his dreams; and Thingol spoke to him of the deep gorge of the River Narog, and the caves under the High Faroth in its steep western shore, and when he departed he gave him guides to lead him to that place of which few yet knew. Thus Finrod came to the Caverns of Narog, and began to establish there deep halls and armouries after the fashion of the mansions of Menegroth; and that stronghold was called Nargothrond. – The Silmarillion, Quenta Silmarillion Chapter XIII Of the Return of the Noldor