I’ve always had a soft spot for the stories that lurk in the damp folds of the British landscape. The ones that skulk just out of sight on a winding lane or cling to the mist at the edge of a mountain path. Wales, to the surprise of absolutely nobody who has ever stood on a slate-grey hillside while the weather attempts murder, has more than its fair share of such creatures. But few are as unsettling, or as wonderfully odd, as the gwyllion.

The name itself has a deliciously slippery feel, capable of conjuring images of gaunt wanderers, spectral women, or whole packs of mountain-haunting spirits, depending on which valley you grew up in and who told you the tale. That’s part of the charm: the gwyllion are not one creature, but a family of shared anxieties and shadowed shapes, all born from life lived close to the wild.

Traditionally, the gwyllion are most often described as female spirits who roam the high roads and lonely paths of Welsh mountains. They are not malevolent in the way that, say, a healthy English ghost sometimes fancies spectral violence; nor are they benign. They exist in that brilliant Welsh tradition of creatures who simply make life very difficult for travellers.

Especially those foolish enough to be caught by nightfall.

A gwyll will appear where the path is treacherous, the fog thick, and your sense of direction already half gone. She will lead you astray, circling you through gullies and crags, bringing you back to the same cursed patch of ground again and again until dawn or despair breaks you.

One of the best-known of these mountain spirits is the Old Woman of the Mist, the Gwrach y Rhibyn’s quieter, more passive-aggressive cousin. She appears on the slopes wrapped in tattered garments, her face half-obscured by hoods or veils of drifting cloud. Sometimes she stands and watches. Sometimes she gestures for you to follow. Occasionally she simply wails – a sound described in nineteenth-century accounts as being

“like a child crying itself hoarse on a cold stone floor,”

…which tells you everything you need to know about the emotional health of the Victorian imagination.

As with all good Welsh folklore, the relationship between human and spirit is not entirely straightforward. The gwyllion, for all their eerie habits, are not immune to rules.

A traveller who keeps calm, resists every attempt to be led astray, and greets the gwyll politely – “nos da i’r hags of the hollows,” as one elderly gentleman reportedly called them – can pass unharmed.

Even more curiously, offering them hospitality may turn the whole encounter around. In several tales, a lost wanderer produces a crust of bread or a shred of cheese, and the gwyll, mollified, vanishes into the mist as if she had never been there at all.

I love that the Welsh solution to supernatural peril is to carry snacks.

Despite their unsettling nature, there’s something human about them too. The gwyllion are often described as straying souls themselves – the restless dead, doomed to wander in a kind of eternal lostness. They echo something ancient in the landscape: a reminder that Welsh mountains are beautiful but never tamed, and that people once walked them with fear as a companion.

Perhaps still do, if they find themselves descending Cadair Idris a little later in the evening than planned.

The Victorian folklorist Wirt Sikes (a man who enthusiastically collected Welsh supernatural tales while misunderstanding most of them) wrote that the gwyllion

“belong to the twilight between ghost and fairy.”

It’s one of the few things he got absolutely right.

They hover in that in-between state, neither banshee nor brownie, neither demon nor guide. Instead, they act as the land’s personification of confusion, cold, and unlit paths. The folklore form of getting hopelessly lost in the Brecon Beacons with a half-charged torch and absolutely no idea where your car is.

What fascinates me most is how the gwyllion reflect the lived experience of Wales itself. You can feel the geography shaping the legend… the steep passes, the fog that rolls in without warning, the lonely shepherd tracks twisting like grey ribbons across the hills. These weren’t just ghost stories;

they were warnings dressed in superstition. Keep to the road. Travel by daylight. Respect the mountain…

And for heaven’s sake, don’t follow strange women who emerge from the mist.

In modern times, the gwyllion haven’t entirely faded. We still invoke them, knowingly or not, whenever we remark on unexpected fog on a Welsh lane or that unnerving feeling of not being alone as the weather closes in. They’re part of a living folklore that thrives precisely because it isn’t trapped in the past. These spirits still wander with us in stories told around fire pits, in social media posts about haunted hikes, and in the imaginations of anyone who has ever glanced over their shoulder while the rain begins to fall sideways.

There’s a certain comfort in them, oddly enough. The gwyllion remind us that the world is bigger, stranger, and far more layered than daily life suggests.

They are the shape of our uncertainties, dressed in ragged cloaks and drifting cloud.

They whisper that even in a time of satnavs and LED headlamps, you can still lose yourself – truly, profoundly – on a Welsh mountainside. And maybe that’s no bad thing.

So the next time you’re travelling over a high pass and the mist begins to thicken, don’t panic. Don’t rush. And don’t, under any circumstances, follow the figure beckoning from the rocks. Give her a polite nod, wish her well, and keep firmly to your path. After all, she might just be checking that you remember your manners.

And if you’ve got a bit of cheese in your pocket, well… you never know when it might come in handy.