With the coming of day he went on again without haste. The sun rose behind his back and set before his face, and where the water foamed among the boulders or rushed over sudden falls, at morning and evening rainbows were woven across the stream. Wherefore he named that ravine Cirith Ninniach.
Thus Tuor journeyed slowly for three days, drinking the cold water but desiring no food, though there were many fish that shone as gold and silver, or gleamed with colours like to the rainbows in the spray above. And on the fourth day the channel grew wider, and its walls lower and less sheer; but the river ran deeper and more strongly, for high hills now marched on either side, and fresh waters spilled from them into Cirith Ninniach over shimmering falls. There long while Tuor sat, watching the swirling of the stream and listening to its endless voice, until night came again and stars shone cold and white in the dark lane of sky above him. Then he lifted up his voice, and plucked the strings of his harp, and above the noise of the water the sound of his song and the sweet thrilling of the harp were echoed in the stone and multiplied, and went forth and rang in the night-clad hills, until all the empty land was filled with music beneath the stars. For though he knew it not, Tuor was now come to the Echoing Mountains of Lammoth about the Firth of Drengist. There once long ago Fëanor had landed from the sea, and the voices of his host were swelled to a mighty clamour upon the coasts of the North ere the rising of the Moon.
— J.R.R. Tolkien, Unfinished Tales, “Of Tuor and His Coming to Gondolin”