Tradition: Welsh Mythology
Alternative Names: Gwyllon
Category: Goblin
The Myth
The Gwyllion are frightening female fairies that haunt lonely mountain roads in Wales. Gloomy and hag-like in nature, they resemble witches or sinister spirits rather than the more benevolent elves of Welsh folklore. They appear to travellers at night or on misty days, causing even those who know the roads well to lose their way. Some Gwyllion utter strange cries and shouts across the mountains, frightening anyone who hears them.
One of the best-known Gwyllion is the Old Woman of the Mountain, a ghostly figure associated with Llanhyddel Mountain in Monmouthshire and Black Mountain in Breconshire. Local tradition held that she was the ghost of a woman who had been regarded as a witch during her lifetime. On Black Mountain, a traveller encountered her walking ahead of him. Whenever he tried to catch up, she remained just beyond his reach, leading him farther from his route until he found himself in a marsh. When she finally gave a cackling laugh, he suspected her supernatural nature and drew his knife. The Old Woman immediately vanished.
Knives and other cutting tools were believed to repel the Gwyllion and other Welsh ghosts and fairies. Travellers who encountered them in the mountains could drive them away by drawing a knife, particularly when the spirits had led them astray. The Gwyllion were also said to visit houses in the parish of Aberystruth, especially during stormy weather. Although people feared them, they provided clean water and welcomed them into their homes to avoid offending the fairy visitors. They took care not to leave knives or other cutting implements near the fireside, where the fairies liked to sit.
Other accounts describe Gwyllion dancing wildly around a traveller on Bedwellty Mountain, accompanied by the sound of a bugle horn and the apparent passage of invisible hunters on horseback. The traveller drew his knife, causing the spirits to disappear. These traditions portray the Gwyllion as dangerous and disorienting supernatural beings, feared for their ability to confuse travellers and disturb isolated communities, yet vulnerable to the protective power attributed to knives and iron.
Sources
“Gwyllion.” Wikipedia: The Free Encyclopedia. Wikimedia Foundation. Accessed October 17, 2026. https://en.wikipedia.org/wiki/Gwyllion