I much prefer the other set of words "In Derry Vale" as mentioned in one of the posts above:

In Derry Vale: by WG Rothery

In Derry Vale, beside the singing river,
So oft I strayed, ah, many years ago,
And culled at morn the golden daffodillies
That came with Spring to set the world aglow.

Oh, Derry Vale, my thoughts are ever turning
To your broad stream and fairy-circled lea,
For your green isles my exiled heart is turning,
So far awa-a-ay acro-oss the-e sea.

In Derry Vale, amid the Foyle's dark waters,
The salmon leap above the surging weir,
The seabirds call – I still can hear them calling
In night's long dreams of tho-o-ose so dear.

Oh, tarrying years, fly faster, ever faster,
I long to see the vale belov'd so well,
I long to know that I am not forgotten,
And there at ho-o-ome in pe-eace to-o dwell.

But lots of info here re the various takes on it:
https://en.wikipedia.org/wiki/Londonderry_Air