I've been holding this one close for a while, now released with a little gentle prodding from Bow.  (I think the words, "It made me cry," was the clincher.)  The meter might be a little shaky, but the sentiment is genuine.

'Mother Idril, I would we had a good Ecthelion of the Fountain here to play to me on his flute, or to make me willow-whistles!  Perchance he has gone on ahead?'  But Idril said nay, and told what she had heard of his end.  Then said Eärendil that he cared not ever to see the streets of Gondolin again, and he wept bitterly; but Tuor said that he would not again see those streets, "for Gondolin is no more."

-The Fall of Gondolin, JRRT  HoME v.II

Great is the Fall

Great is the Fall of Gondolin, ye of Seven Names and fair,

Whose thoughts and songs are lammentations rising in the air.

Great were her lords and captains arrayed in splendor sallied forth

In mail and hauberk gleaming through the dark winds of the North.

Weep ye now, O Gondolin, scoured beneath the skies

For thy fallen lords and captains now in death hath closed their eyes.

Where now is thy Turgon-King who built thee great and fair?

He hath perished in his tower, his folk upon the stair.

Great is the Fall of Gondolin, and great the fall of her King

The lord whose lammentations now all ye exiles sing.

Weep ye now, O Gondolin, upon the vale in flower

For thy mighty Turgon-King hath perished in his tower.

Where now is fair Ecthelion whose voice was sweet to hear?

He gave his life to slay his foe in the fountain waters clear.

Tears unnumbered shall ye shed, tears now beyond count

For Ecthelion beloved hath perished in the fount.

Weep ye now, O Gondolin, no towers now to soar

For Ecthelion beloved shall wind his flute no more.

Where now is golden Glorfindel? Who of his House be left?

He hath faced his final dreadful foe upon the Eagle's Cleft.

Farewell O Glorfindel beloved, thy name forever blessed

'Neath stone and song and elanor we lay thee here to rest.

Weep ye now, O Gondolin, and many songs be wrought

For brave and mighty Glorfindel whose life ye safety bought.

Where now is brave and stalwart Rog? Where be his Hammer of Wrath?

They hath perished out upon the plain through foes their hard-hewn path.

Forth his fearless warriors marched in battle hard and long

There fell defending unto death that once-fair Stone of Song.

Weep ye now, O Gondolin, whose flight Rog's valor earned

Never more now than a memory - of that house, not one returned.

Where now be thy mighty captains, thy lordlings at thy call?

They hath gone to find their final sleep and peace in Mandos' Hall.

Whither now, O Gondolin, shall the exiles turn their feet

And the weary path now tread, our cursed fortunes meet?

Weep ye yet, O Gondolin, but hasten now thy flight

Lest the Noldor perish utterly and vanish into night.

Notes on 'Great is the Fall':

The success of this poem I think depends on the strict formula I used for the verses.  'Where is Such-and-such?  He hath perished.  He fell doing this-and-that.  Mourn for him.'  In the back of my head I must have had the poem of the Rohirrim.  "Where is the horse and the rider?  Where is the horn that was blowing?…They have passed like rain on the mountain, like wind in the meadow." 

Originally there was also a verse about Maeglin's treachery, done in the same formula as the others.  I removed it after deciding that the exiles would not have mentioned his name among their fallen heroes, not even in scorn.  Although The Fall of Gondolin is one of my favorite storylines by Tolkien, and the romance of Tuor and Idril my favorite element of that story (okay, after Glorfindel), I resisted the temptation to extol their deeds as well.  This poem is a song to the heroic departed, and no one else.

Yes, I know that Duilin and Penlod were also killed during the fall of Gondolin.  I tried hard to make verses for them, even one shared verse, but it just wouldn't come.  I couldn't find enough original material on them to evoke the same gut-clenching sorrow I felt over the deaths of the others, and I figured it was better to have no verse than a poor one.  I may attempt it again someday.

Concerning Turgon, I have always had mixed feelings about his part in the fall of Gondolin.  He did not do the sensible thing (which would have been flee), nor the heroic thing (which would have been fight), but he did do the kingly thing, which was join his fate to his city's.  If he had not had Tuor to entrust his people to, he might have acted differently, but who knows?  So much of himself had gone into the building of Gondolin, he might have died of grief anyway had he fled.  Like his father, Turgon looked upon his death and knew it for what it was, and faced it honorably as he could in the way that seemed fit to him.  Although he had no particular deed to his credit from the last battle, his people would have nonetheless given him a hero's requiem after his fall.

I've no plans to render this poem into Elvish.  I know nothing of the languages & wouldn't even know where to begin.

I'm very interested to hear what you all think of my first published non-humor effort.  Please review!

PS – The Silmarillion Owner's Guides will shortly be back up in their shiny new story frame!