Are you brave enough to spend a night on this Welsh mountain?

Idris Gawr was an early-medieval king of Merionydd — at that time, a kingdom in the southern mountains of Eryri (Snowdonia). According to folklore, he also happened to be a giant whose nightly habit was to climb the great mountain that towered over his lands, his footfall setting the ground quaking. As he neared the summit, he’d place his enormous royal bum in a great cavity and rest his long back against a sheer wall of Ordovician rock. And up there — secluded midway between heaven and earth — he’d contemplate the turn of the constellations, the ascent of certain stars. As well as meditating on celestial matters, he’d ponder the fate of mortals: those subjects sleeping beneath his giant feet. Idris was a king, a giant, an astronomer and a philosopher. His story straddles fact, folklore and fantasy, but his name clings on as a real-life location in southern Eryri — a mountain known as Cader Idris: ‘Idris’s chair’ in Welsh.

Stand on Cader Idris’s summit today and you start to appreciate the dimensions of the giant’s chair: the windblown ridges that would’ve served as armrests; the glacial cirque large enough to accommodate a backside a mile wide. In the 21st century, a tradition endures that this is a mountain for meditation — a summit to be scaled before resting the body and exercising the mind. A Welsh proverb has it that anyone who spends the night asleep on top of Cader Idris will wake either a poet or a madman (some sources also offer a third possibility: death).

So, one winter morning, I stuff my thickest sleeping bag in a rucksack and then stuff myself on a train bound for Mid Wales. I intend to plant my hiking boots in Idris’s giant footsteps, scale Cader’s Idris and sleep overnight on its summit. I plan to put this proverb to the test.

A mountain kingdom

Cader Idris is an 893-metre peak at the southern edge of Eryri National Park. Most sizable peaks in the range are to the north, a members’ club clustered around Yr Wyddfa (Snowdon) itself. Cader is a lone wolf outside of the pack — its supremacy unchallenged by the hills that hunch around its base. The mountain’s southern flanks do resemble a chair, although its northern aspect is more akin to a castle — a long rampart of rock, crenelated by crags and boulders.

It’s also moated on three sides by water: to the west by the saltwater of the Irish Sea, to the north by the brackish tides of the Mawddach Estuary. To the south is the freshwater lake of Llyn Mwyngil, in whose silver expanse the mountain’s reflection trembles. Cader is a formidable but popular climb — at its shortest a five-mile there-and-back hike — and it’s doable in a day for the sensible majority who dare not risk a night on the mountain. Part of the appeal is in exploring this less visited, more sparsely inhabited corner of Wales — Idris’s erstwhile kingdom of Meirionnydd, set in the shadow of the mountain.

My afternoon train from Birmingham chunters west along the Cambrian Line — beyond the border, the gentle hills of the Welsh Marches graduate to high, glowering moors. The carriage ploughs into a blizzard of falling leaves; trees rake their twiggy fingers against the windows. Four railway lines plunge into Wales from the English border — two cling to the coast while a third veers south. The fourth, the Cambrian Line, is alone in charging squarely into the heart of the country — its single-track line swerving amid steepening contours en route to Cardigan Bay. We pass villages of slate and pebbledash, and conifer plantations with thick shadows under the canopy. By the time I eventually disembark in the little town of Machynlleth, Cader’s summit is obscured in evening clouds. Before I climb, I need to speak to someone who’s made the overnight pilgrimage before.

“Most people say I’m mad,” says Laurence Main, stroking his sorcerer-like beard. “But then I think most people are mad, too. Especially poets.” Laurence is a druid and a spiritual seeker who’s slept on the summit of Cader Idris 24 times. I meet him the following morning in a quarryman’s house in Cader’s foothills where he’s lived since 1981. Over a plate of digestive biscuits, he recounts the time, in June 1996, he fasted for a week on the mountain, and the mornings he awoke to find an inversion, the summit floating “like a boat on a sea of cloud”. He also tells me he’s often experienced prophetic dreams on Cader Idris. “It’s a stimulating and challenging mountain,” Laurence says. “You’re dealing with intense energies that can affect people.”

Cader Idris is rich in folklore but it’s also revered as a sacred mountain by a small, committed New Age community. Laurence points me to an esoteric school of thought that hails Cader as the centrepiece of a landscape zodiac — a star map imprinted on the Earth, which some attribute to a lost civilisation that predates the Ice Age. It’s a theory without basis in historical fact but it does reveal something of the power the mountain can exert on the imagination. Six years ago Laurence collapsed while descending the mountain — his knee cartilage wearing out after a lifetime of roaming. He’s not climbed it since.

“I’m 75 now,” he says. “And I’m going to get older. The years are coming rapidly. But I’ve been told I’ll make one last ascent of Cader Idris, so I’m saving up my knees. On the mountain I feel in tune with a much longer story. I feel welcome.”

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Stairway to Heaven

After leaving Laurence, I start my climb up the mountain’s Minffordd Path. Initially, stone steps ascend through sessile oak woodlands, rotten acorns squidging underfoot. Waterfalls gorged on torrential rain tumble past me — their courses flailing like the manes of white horses in the wind. Eventually the path rises over the treeline. Guarding the high pass is a single rowan — leafless but still adorned with the bright red berries of summer. Beyond it, all colour seems to drain away from the world; a realm of bare rock, mystery and mist beckons.

There are other presences on Cader beyond Idris. Welsh folklore has the mountain as the haunt of the Brenin Llwyd — the so-called ‘Grey King’ — a spectral figure formed of fog, prone to preying on lost travellers. In her 1899 book From Snowdon to the Sea, Welsh writer Marie Trevelyan recounts the tale of a ‘Lord of Meirionnydd’ who spent the night on the mountain hoping for enlightenment like Idris. Up there, ‘cut off from the lower world’, he heard a disembodied voice warning him away from ‘the secrets of the stars’. After descending, he glimpsed a grey figure watching from the summit from which he’d fled. Although perhaps he’d gone mad.

It takes around two more hours to climb a curving ridgeline and follow it to the top of the mountain. By lunchtime I’m scrambling over scree and stumbling through rags of mist, and by late afternoon I reach the summit trig point. Beyond it lies the stone hut where I plan to stay the night. It was originally erected as a refreshment stand for Victorian travellers who arrived on ponies; it now serves as an emergency shelter, minus a door, meaning clouds trespass within. Curious sheep have also been known to nuzzle at people dozing inside. Groundwater pools on the slabs, cobwebs lace the windows, moss furs the lintels. There’s no view to be had — only a purgatorial whiteness all around.

Some days earlier I’d spoken to Bristol-based writer Samatar Elmi, who last climbed the mountain on a clear summer day — an experience that inspired a poetry collection entitled The Epic of Cader Idris. He believes the boundary between poet and madman could be a thin one. “The power of the mountain is obvious,” Samatar told me.

“The gift of climbing it is that you’re able to see much further. But, in another sense, it means you see your own life in a much clearer way. The myth of Idris gets under your skin. We live in a world that’s so material that it’s no surprise we need the opportunity to escape into enchanted realms of possibility.”

Sleeping dragons

Dusk reaches the shelter. Mice emerge from the stonework. Come nightfall, driving rain crescendoes into a full-blown storm. In my bed high above the world I slip into a shallow sleep. Sounds intrude into my dreams: the horn blast of wind booming through loose slabs, the rattling of the corrugated iron roof, like a poltergeist in the attic. Mountains and dreams are common bedfellows in Welsh folklore. Stories tell of slopes where Arthur and his knights sleep, waking only in the nation’s hour of need; other hills are said to be abodes of slumbering dragons. To sleep on Cader might, then, have been a way to gain admission into this mythic dreamland. Others say the ‘poet or madman’ proverb stems from old bardic tradition, that in the unrecorded depths of Welsh history poets would climb to these wild heights to solicit visions. In the presence of such powerful elements, their minds would be ignited by the lightning fork of inspiration, or else be overwhelmed by the power of the mountain storm. They would become masters, or else be mastered.

Morning comes — the weather is calmer. Wondering about the proverb, I put pen to paper with frozen fingers — but no words flow. I wonder if anything has changed at all. After breakfast the clouds part, revealing green fields and coppery moors. Tiny cars inch along the A-road far below as I make my descent. At the lone rowan tree, I take one last glance at the mountain; at the enclosure of the giant’s chair; at a lone raven circling; and also at a lone hiker just visible on the distant summit — a soul who would have had to start improbably early to reach that vantage point and who must have taken a different route than I had, because I hadn’t passed them on my way down. That figure stood a while on the precipice before disappearing, cloaked in mist.