Deeper And Down | We Rode The World’s Longest Underground Zipline 400m In An Abandoned Mine

Sometimes the wildest adventures are on your doorstep (or under it)

Words by Helen Abramson

Let’s face a simple fact: nobody thinks ziplining is cool. The idea of it is grand, rushing through the air like you’re flying, whizzing over vast chasms of beautiful scenery… But the reality is usually pretty tame. For anyone who doesn’t mind heights and is a sucker for adrenaline rushes, a day out on a standard ziplining network up in woodland treetops, while significantly more enjoyable than a day chained to your desk, will probably leave you under-thrilled, underwhelmed, and perhaps even a little dead inside.

Yet after years of disappointment, I never gave up on the idea that ziplining could be really exciting. It should be. The South Park episode I Should Never Have Gone Ziplining may have filled me with putrid shame from it all, but I still wasn’t deterred. And then, at last, I found that my gut might have been right all along: there was a zipline-shaped pot of gold in the adventure-sports hub of Snowdonia, north Wales. I didn’t even have to get on a plane.

Credit: Helen Abramson

This region is a slate graveyard; you can barely move for piles of the stuff. In the late-nineteenth and early-twentieth century, north Wales was the slate-mining heartland of the country. The longest underground zipline in the world lies here, in the blackness, deep down in one of these mines. It’s part of a 5km network of nine ziplines only accessible via several traverses, scrambles, climbs and abseils. You enter the blackness for fun, wondering what level of hell the miners endured for most of their short lives, and at some point you stand in the deepest publicly accessible point in Britain, nearly 400m below the surface.

“You enter the blackness for fun, wondering what level of hell the miners endured for most of their short lives…”

Back above ground, 20km away, the world’s fastest zipline, Velocity, flies people high over the mounds of grey slate, whizzing passengers across at an incredible maximum speed of 190kmph, equivalent to a belly-to-earth skydiver’s terminal velocity.

I decide to warm up with Velocity. My excitement levels have risen dramatically, and I’m all in. It’s run by ZipWorld, a steadily expanding giant-adventure-playground empire. They operate a range of ziplining and adventure courses, but Velocity is the main event, what with its world-record-holding speed limit. The vertical drop is over 200m, and at 1.6km the line is the longest in Europe.

The warm up to my warm up comes in the form of Little Zipper, which takes you at a maximum of 65kmph over a 420m line, measly by comparison to its big sister, but just a few metres shy of the longest zipline in the UK until Velocity came along. I’m positioned head first, and my Bob-the-Builder-style harness is securely attached. I feel like a human cannonball. However, it’s surprisingly comfortable compared with the usual crotch-grabbing upright harnesses that leave passengers in whirlpool-like rotations.

The cheery staff shout out my weight, written on my wristband, to each other, before yelling it down a walkie talkie. Marvellous. They count down from three and unlatch two of us simultaneously. We zoom over the treetops at a comfortable speed, before being lowered down by staff and unleashed. It’s a short hop into a truck that crawls painfully slowly up the mountainside to the top of Velocity.

“I feel like a human cannonball.”

I’m strapped into the same pulley system, my weight is casually banded about again by several staff members, and I’m counted down and released. Momentarily, I consider what might happen if the system breaks while I’m 450m above the earth; it’s not a pretty mental picture. I remind myself that the breaking strength of the cable is 27.7 tonnes, which, despite those recent humiliations, is still significantly heavier than me.

We’re shot out of the starting points in pairs again, and I pick up speed quickly, insanely quickly, as the treetops, rocks and earth all blur into one, before bursting out over the glimmering turquoise quarry lake. It’s so magically surreal that I have to mentally slap myself to stop comparing it to a virtual reality film. I click through the brake system and land easily and safely.

It’s by far and away the most enjoyable zipline I’ve ever done, and I’m pumped. Yet it wasn’t actually that scary, and it certainly wasn’t a physical challenge: that will come underground.

The following day before heading to my next ziplining gig, I make a quick to detour to another ZipWorld base at Betws-y-Coed. For a tenner, you can hurl yourself off the top of a 31m tree and plummet to the ground, attached to a chord with powerfan technology that allows you to simulate the feeling of a skydive freefall, slowing you down before you land. The tree looks nauseatingly tall. I’m not generally afraid of heights, and I’m usually the annoying one elbowing to the front of the queue when the opportunity for an adrenaline-pumped activity arises. But this simple lanky tree, practically in the middle of the car park, has unnerved me.

I steadily climb up the trunk using the handy metal stirrups, making absolutely sure not to look down. I’m clipped in at the top and before I know it my toes are over the edge and I’m stepping off, absolutely petrified that I’m going to die a horrible death in a messy heap on the car-park floor below. A few seconds later, I’m still alive, in one piece, and ecstatically high on the rush. The fall wasn’t stomach wrenching, as I had imagined, instead it felt rather floaty.

“At Velocity, there was a café, glossy posters and billboards, loads of people milling around…here feels like the middle of nowhere…”

Still elated, I pull into another a car park for my final nerve trial. I’m near the historic mining town of Blaenau Ffestiniog for the Go Below Ultimate Xtreme underground ziplining adventure. At Velocity, there was a café, glossy posters and billboards, loads of people milling around, a cosy reception, children playing and dozens of staff. They funnel groups of ten people through every twenty minutes. Here, it’s a rather different story. It feels like the middle of nowhere. There’s no office or on-site café, just a flimsy sign, a rickety equipment shed, two trip leaders and a group of seven lads, one of whom is being sick. It transpires that I’ll be spending the rest of the day down a mine with a viciously hungover stag group. If I was apprehensive before, I’m full-blown anxious now.

Ewan and Duncan, our guides for the day, give us a warm welcome, kit us up with helmets, harnesses, wellies and head torches, and we march uphill for half an hour or so, through a quiet hamlet and past a pretty lake, while Ewan makes a continuous string of terrible jokes. Fortunately, he’s pretty serious about mines. “I spend most of my time underground; I’m a caving instructor, too, but I prefer the mines. There’s so much to explore down here – today we’ll only see the tip of the iceberg.”

When we’re anywhere near a drop (which is most of the time), we’ll be attached by at least one of the cow’s tails, dangling karabiners, on our harnesses, which means we’ll never fall far. The boys have stopped chucking up, and we head into the abandoned mine.

“The boys have stopped chucking up, and we head into the abandoned mine.”

The first thing that hits me, before the darkness encloses us, is the damp cold. I layer up, and we tread carefully down slippery rail tracks, past an old crashed cart. I’m grateful that there aren’t any constricted, narrow tunnels to crawl through, so it rarely feels claustrophobic. Go Below have left things as much as possible as they are down here, they haven’t added lighting and sturdy bridges or extra platforms. However, they have added occasional extra ledges and iron rungs to help ascend steep rock faces, and, as you’d expect, safety cables and ropes are funnelled through hundreds of metal hooks, plus of course there are the nine ziplines.

Our first zip is the record-holding longest one, Goliath, at 130m – not that long by normal standards, but the angle is treacherously steep. It’s a comfy ride though, as it has a convenient seat contraption. Duncan test-rides it into the abyss, and hollers once he’s down. I can see his light bobbing around on the other side, and the drop below doesn’t seem too far. It’s fast and fun, much like a rewinding, speeded-up chairlift.

Credit: Go Below

As we trudge through tunnels and into huge caverns, sometimes wading through knee-deep water, we pass the odd tobacco pipe, cup or pickaxe left by Victorian quarrymen. The eerie atmosphere is spiked with Ewan’s almost constant whistling of the Kill Bill theme tune. In between the whistling, he and Duncan fill us in on some of the fascinating history of this place, highlighting the preposterous dangers of working down here a hundred-odd years ago.

“It’s difficult to believe the majority of miners didn’t die from fatal accidents in here.”

Life expectancy for miners here was 35; though there were terrible accidents, the men were usually killed off by lung problems, from breathing in the noxious gases and dust for too many years. They worked six days a week, and were obligated to attend church on Sunday mornings. Half a day off, and then straight back to the mines. “It wasn’t far off slave labour,” Ewan adds. Sometimes, the twenty-first century can actually look quite appealing.

It’s difficult to believe the majority of miners didn’t die from fatal accidents in here. The workers had to pay for any safety equipment, even something as simple as a piece of rope, out of their own underpaid pockets. The via-ferrata traverses we do, over sheer drops of 10, 15, 20m or more are nail-biting enough with our secure systems in place. The thought of having to tackle these daily, not roped in, with barely anything to hold onto, is nightmarish.

The stag group perk up as the day wears on. The climbs are sometimes tough, slippery, with long reaches, and I need to do some deep breathing to stay calm. We cross rotting bridges made from whole Canadian tree trunks over a century old, clinging onto the ropes and trying not to look down into the blackness. One of the ziplines starts from the “diving board”, a piece of old railroad literally sticking out into nothingness. Trusting the equipment is the only way not to lose your nerve.

The Victorian miners had to pay for lighting themselves as well as safety gear, so they used to bring down their own candles. We all turn off our head torches for a couple of minutes to get a true sense of the blackness. It’s inky thick. Ewan explains that our eyes would never adjust to this darkness, because the rock doesn’t let any light rays through. Standard low-light night vision goggles would be useless down here, you’d only be able to use thermal imaging. “Having enough light was crucial for the miners’ survival. Run out of light, and they’d have had it.”

Boys as young as 9 or 10 were drafted into the mines to carry cartloads of slate up and down the shafts. The youngest and smallest of them were given the unenviable task of carrying boxes of gunpowder, while holding a candle. It seems utterly absurd now, but it followed a cruel logic back then: the boys were the most inexperienced, unskilled workers, and thus the most dispensable and replaceable.

Time seems to pass more quickly underground. Before I know it, we’ve been in there all day, almost seven hours. It’s time for the final challenge, the literal leap of faith: a 21m jump, attached to another freefall device. We line up uneasily. When my turn comes, I step forward expecting to see the others at the bottom, but the strange angle means all I see is, once again, blackness. Ewan passes me an elastic cord, clips me in and says, “Jump!” Before I can overthink it, I push off obediently for the second time that day and am surprised by the sudden feeling of dropping like a bullet, somehow more shocking than the treetop fall. The brake-system kicks in just before I reach the ground, bringing me to a smooth landing, my head buzzing.

As we emerge with big smiles into the fading daylight, the warmth feels like walking off an air-conditioned aeroplane into the tropics. The air smells good. It’s been a remarkable and very draining couple of days. It’s official: ziplining adventures can be wild, after all… especially if you throw a bit of freefall in.

Credit: Go Below

To read the rest of Mpora’s Wild Issue head here 

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  • Trains from London Euston take just over three hours via Chester to Llandudno Junction, at the northern tip of Snowdonia National Park.
  • Having a car to get around the different sites is a lot easier than relying on buses, and cheaper than taxis. Avis have a rental point at Llandudno Junction station.
  • Stay overnight at the cosy Eagle’s Bunkhouse in the quaint village of Penmachno, near Betws-y-Coed, for £19 a head.
  • Go Below Ultimate Xtreme costs £79 and takes all day; weekends book up fast, so plan in advance.
  • Zipworld’s Velocity is at Bethesda; it costs £60 and takes 2 hours. Plummet is at Betws-y-coed; it costs £10 and takes about 10 minutes.


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