"Myddfai Parish in Carmarthenshire [Wales] was in former times celebrated for its fair maidens, according to an old rhyme which records their beauty thus..."

Notes

(1) "Ferdre could refer to Llanilltud Faerdref (the 'ae' turns to 'e' in the old Gwenhwyseg dialect of the South East and Valleys), but there are probably a few Faerdrefs in Wales." -Commentator on Reddit

(2) Myddfai is famous for the legend of "The Lady of The Lake".

Thanks and Acknowledgements

This rhyme can be found in "Folk-Lore of West and Mid-Wales" (1911) by Jonathan Ceredig Davies. The translation is slightly changed from the one there. The rhyme and translation can also be found in print in 1878 in "Y Cymmrodor". It's already referred to as being old back in 1878.