One of the longest Quenya texts, it was sung by Galadriel when the fellowship departed Lórien. Also called Altariello nainië Lóriendessë in Quenya.
Galadriel's lament is a very complex and beautiful composition. It is the longest Quenya text in the The Lord of the Rings and also one of the longest continuous texts in Quenya that was ever written by Tolkien. He revised it many times before reaching the form that was published.
An excerpt from Helge Fausganger's analysis which is still available on his website:
In The Road Goes Ever On (RGEO) the poem is given in three versions. The first is Namárië written in Tengwar, our only substantial example of a Quenya text in Elvish writing. The two other versions are given in RGEO:66-67. One is (nearly) identical to the text in LotR, but Tolkien has added accent marks, denoting all major and minor stresses. It is followed by a version with an interlinear translation. The latter version differs somewhat from the other texts, mainly in word order, because Tolkien re-arranged it to "a clearer and more normal style". He explained that the text in LotR has a "poetic" word-order and style, making concessions to metre.
Tolkien provided a translation in the Lord of the Rings, but please bear in mind that the translation can't be matched perfectly with the texts in Quenya since the word order is not the same:
Ah! like gold fall the leaves in the wind,
long years numberless as the wings of trees!
The long years have passed like swift draughts
of the sweet mead in lofty halls
beyond the West, beneath the blue vaults of Varda
wherein the stars tremble
in the voice of her song, holy and queenly.
Who now shall refill the cup for me?
For now the Kindler, Varda, the Queen of the stars,
from Mount Everwhite has uplifted her hands like clouds
and all paths are drowned deep in shadow;
and out of a grey country darkness lies
on the foaming waves between us,
and mist covers the jewels of Calacirya for ever.
Now lost, lost to those of the East is Valimar!
Farewell! Maybe thou shalt find Valimar!
Maybe even thou shalt find it! Farewell!