Literature, History, Heritage

Of Mermaids and Fairies

Fairies are frequent characters in stories from across Wales. The fairies known as Plant Rhys Ddwfn sometimes appear as mermaids in Pembrokeshire folklore.

seventeenth-century woodcut of a mermaid
Jacobean mermaid: ‘A most strange and true report of a monsterous fish, who appeared in the forme of a woman, from her waste upwards by P.G.’ relates the sighting of a mermaid near Pendine, Carmarthenshire, in 1603. ~ Source: National Library of Wales ~ Creator: W. B., London ~ Date: 1603

In Pembrokeshire, fairies are commonly known as Plant Rhys Ddwfn, the ‘children of Rhys the Deep’, ‘deep’ here referring to depth of character. This particular tribe or type of fairies are of diminutive size like that of a 5- or 6-year old child. Sometimes, the females are half human and resemble mermaids. They are said to live on a number of islands stretching across Cardigan Bay, from Pembrokeshire in the south to the Llŷn peninsula in the north. Rhys Ddwfn’s island realm is invisible to the human eye, except when viewed from one particular spot at Pen Cemaes, about 20km north of Fishguard. According to legend, a special herb grows in a patch no more than a metre wide; from that viewpoint, the islands would uncover themselves to human eyes.

ink drawing of a mermaid in the margins of a medieval manuscript
Medieval mermaid: Illustration by an unknown artist of a mermaid in the margins of a copy of the Welsh manuscript Laws of Hywel Dda, fourteenth century. ~ Source: National Library of Wales ~ Creator: Unknown

For a long time, the Plant Rhys Ddwfn went to market in Cardigan. No one ever saw them coming or going; they were just there, gladly paying the traders good money for the wares on offer. Whenever prices were high on market day, it was said that the Plant Rhys Ddwfn had been in town. This did not make them favourites with other buyers, who had trouble stretching their little money to make necessary purchases, and so the fairies started visiting Fishguard market instead. In 1896, the Pembroke County Guardian reported the statement of a Fishguard woman who acknowledged their presence, however further to the east, saying, ‘There are fairies for they came to Ha’rfordwest market to buy things, so there must be.’

beach scene on Goodwick Sands
View of the entrance to Fishguard, from Goodwych sands Octr 1st 1814: A beach scene showing people in various activities. A man and woman are possibly carrying a basket of fish or cockles. ~ Source: National Library of Wales ~ Creator: William Daniell (1769-1837) ~ Date: 1814

On other occasions, the Plant Rhys Ddwfn appeared around the Fishguard area as mermaids sitting on rocks and combing their hair. In 1858, Daniel Huws supposedly encountered a mermaid between St David’s and Fishguard. Except for her fishtail she was said to look ‘like the lasses of Wales’ and spoke Welsh to the men who approached her, before she disappeared back into the sea. At another occasion, a mermaid was spotted outside Fishguard at Llanwnda, where in 1798 the French had made an unsuccessful attempt at invading Britain. The men who saw her abducted her and took her home with them. She only regained her freedom in exchange for three bits of advice which were remembered in the family ever afterwards.

photograph of the cliffs at Pwll Deri
The cliffs near Pwll deri: After ransacking Garnfawr Gottage at Pencaer, the mysterious lady is said to have made her escape to the cliffs of nearby Pwll Deri and returned to her watery home ~ Source: Wikimedia Commons ~ Creator: Lesbardd ~ Date: 2014

In 1910, another local newspaper, The Pembrokeshire Herald and General Advertiser, reported a strange occurrence in Pencaer, Fishguard. A heavily veiled woman barged into Garnfawr Cottage, which at the time was empty except for a little girl. The girl watched the woman go from room to room, rifling through all the family’s possessions as if she was searching for a lost item, but taking nothing. She then climbed the ladder to the crog loft, but was trapped by the little girl removing the ladder. Despite this, the woman escaped by jumping through one of the windows and leaving no trace. Owing to her odd dress and behaviour, it was thought that Garnfawr Cottage had been visited by a mermaid who had emerged from the sea at nearby Pwll Deri.

1808 pencil drawing of lower town Fishguard
Fisguard from the Northside of the Harbor: A pencil sketch of Fishguard, showing the old harbour below and the town extending on the opposite hill. ~ Source: National Library of Wales ~ Creator: Unkown ~ Date: 1808


  • Rhys Ddwfn’s invisible island realm roughly overlaps with Gwyddno Garanhir’s ancient drowned kingdom, the famous Cantre’r Gwaelod of Cardigan Bay.
  • There have been suggestions that the Plant Rhys Ddwfn are, in fact, Irish traders who crossed the Irish Sea to sell their wares at Welsh markets.
  • The island Grassholm, in Welsh Gwales, is one of the mythical islands in the Mabinogi. According to legend, Bendigeidfran’s head rested here for 80 years after his battle against the Irish King Matholwch. Grassholm is believed to be part of Rhys Ddwfn’s kingdom.

Further reading

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Of Mermaids and Fairies by Rita Singer. The story was originally published on Ports, Past and Present on 5 August 2021 is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

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  1. Natasha de Chroustchoff 3 October 2021

    Hi there! May I be so bold as to mention the fairly well-known legend of the mermaid of Treseisyllt farm near St Nicholas on Pencaer? Many local people seem to be familiar with it.

    “According to tradition, a mermaid was carried from Aber-bach to Tresisyllt farm.
    Carried from the sea, she warned the locals that if they didn’t return her to the waves, some awful event would smite the area. She was quickly returned. This is J Howard Hughes’s version of the tale in his book ‘O Fryn Dioddef’ published in 1966.
    There are several other versions of the story. Some speak of the mermaids curse leading to no children being born in Tresysillt for decades.”
    Versions of this tale can be found in several places on the internet (although they may all originate from one source) for example
    (The fact that their a numerous variations in the way the name of the farm is spelled makes searching difficult.) This is it:

    • Rita Singer 3 October 2021 — Post Author

      Thank you, Natasha, for sharing this story! I had come across it before, but as it happened, I’d forgotten to scribble down my source. Coupled with not remembering the name of the farm and it was a doomed endeavour from the start. So I am particularly happy that you have brought the farm name back to my attention.

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