• Overground/underground - a caving archaeology project in the Yorkshire Dales

    1st June 2-4pm at Dales Countryside Museum in Hawes.

    Click here for more

Ario Caves Project


Active member
Hey all,

Just an update really to say that the ACP expo is back after a few quiet covid years.

This year we're finally back into C4 to continue the many upstream leads and to continue climbing a few impressive shafts.

and also as a very special treat we're going back into Cabexa Muxa.

Cabeza Muxa was last visited by a UK team in 1988 when at the bottom of the 900m deep cave the downstream sump (water filled passage) was dived by Rick Stanton to a depth of 33m using scuba gear. It has remained unexplored since then and offers the potential for a significant hydrological connection. The cave contains the largest stream way in the area and the water here is believed to drain to Cueva Culiembro in the Cares Gorge. The end of Sima Cabeza Muxa and Culiembro are about 1,500m apart with a height difference of about 200m. We will plan on re-rigging Cabeza Muxa to facilitate continued cave diving exploration in the downstream sump using closed-circuit rebreather technology. Exploration of the Sima Cabeza Muxa watercourse could provide an important connection between two major deep caves in the area and this would allow a fuller understanding of the hydrological connections and drainage in the region. In turn, this will support and enable future exploration efforts in the area as part of the multi-generational effort to map and understand the cave systems of the Ario plateau.
C4 was first explored in 1996 and 1997 and became the focus of the 2015-2017 expeditions. Finally, in 2017 a major breakthrough was made when the cave, which drops into a major stream way called ‘Underground Overdrive’ was connected to the main watercourse in another cave called ‘2/7’. Upstream C4 has split into a number of passages, chambers and avens, many of which are ongoing and should allow a connection with other important caves in the area as well as other potholes feeding into the upstream end of the system. With several ongoing passages, much work remains to be done in upstream C4 in search of the ‘Ario Dream’

Chris J

Active member
On the 16th-17th July and then again on 23rd-24th July the expedition team met up for some pre-expedition caving and bag packing. Luckily the YDG barn was an ideal venue for getting lots of gear out.

The 2km of UK caving and Spanset rope was washed, pulled through a stop and packed into bags. Through bolts were placed on to hangers with mallions in bunches of 5 and drill batteries charged, tested and packed with drill bits. Dehydrated food for underground camp purchased, mixed and packed and lots of surface and snack food packed into drums. All of our kit will be flown up to Ario in a helicopter so we can maximise caving time so that means everything needs to be packed ready for transport once we arrive.

On Saturday 23rd the final pack into my van was done. Thanks to petzl for the sponsorship of lots of shiny yellow bags!

We intend to update this thread over the next few weeks, expedition starts this weekend!



Active member
Most things worth while start with a dream and taking a chance.

Over 60 years ago now @oxford_uni_caving took a chance on a previously unexplored area of limestone in the Picos de Europa, and boy did it pay off :)

Their efforts have resulted in the discovery of 10’s of kilometres of super deep, stunningly beautiful virgin cave, no human being had ever seen before.

Excited for Chris as he hopefully pushes beyond Ricks limits of exploration in Cabeza Muxa.

Stayed tuned on here for updates


Well-known member
As requested by Chris (he is a little conscerned about fitting all the kit in his van) I have managed to slim down the camera gear to just 4 bags and a box....plus 1 pair of expedition underpants!
Very much looking forward to helping document this years Ario adventures and playing on all that lovely Spanset Rope!


Active member
Nice work chunky, but from the photo it looks like you may have forgotten the underpants - Just Saying!


Active member
We’ve written our recruitment letter ;-)

Volunteers needed for a month to provide support for a cave diving expedition in a deep cave in the remote mountains of the Picos.

Hours of graft: Shifts will be in multiples of 2 - 3 days with maybe a couple of hours of sleep a night

Accommodation: who knows, no one’s been there before 🤣 likely Premium floor space between boulders in a 6oC cave, daran drum toilet and free of charge cold water experience provided by the caves streamway

Role: You will be required to lug 100’s of kilos of equipment up a pathless mountain in 40oC heat then down a 1000m deep cave. Must be very strong physically and mentally and motivated to withstand suffering towards a goal with no guaranteed outcome. Must not be afraid of the dark or enclosed spaces.

You are likely to be suffer hypothermia, hypoglycaemia, trench foot, severe crotch chaffage, loss of will to live and delirium due to sleep deprivation, and must be able to adequately manage the pre-existing complex mental health issues that would precipitate ones spending their precious holiday on such an extraordinarily grim act of self harm.

Skills required: Must be very proficient at rope work & ideally with expedition experience, mountain savy and confident navigator on razor Karst in the mist at night, have cave rescue experience, first aid qualified with extreme wilderness medicine, doesn’t feel the cold, has no sense of smell, a stomach of steel, can remain jolly in the face of long shifts and accruing sleep deprivation and is generally mad.

No Fuel expenses paid, no allowance for PTSD counselling.

Subpopulus Hibernia

Active member
Cabeza Muxa: A frontline report.

One of the two main objectives of this years Ario expedition is to re-bolt and re-explore the cave of Cabeza Muxa, a ~930m deep cave first explored in the late 70s and early 80s by a group of Catalonian cavers from the SIE club. Unlike many alpine cave entrances, Muxa is found at the bottom of a huge 100m wide doline, at the bottom of which a series of huge shafts drop away to a depth of 600m, reaching a dramatic stream passage. This can then be followed for almost two kilometres, dropping another 300m and ending at a sump. In the late 80s this was dived by Rick Stanton, with small cylinders and in a wetsuit, to a depth of 30m.

Since then Muxa has lain unvisited. Later exploration on this side of the Ario plateau focused on the cave of La Texa, which filled in much of the distance between the Muxa sump and the rising of Culiembro. The plan this year is for Chris Jewell to dive the sump with a modern rebreather, and hopefully he will pass the sump and explore beyond as far as he can towards the nearby La Texa. The Muxa infeeder in La Texa was explored in the late 2000s as far as the foot of a waterfall, and the grand plan is that a future expedition to La Texa will be able to scale this and link with the passage explored by Chris. If all this plays out as planned, then attention can turn to linking La Texa to Culiembro, as part of the multi-generational effort to tie all of the major Ario caves together into a vast mega-system.

And so, to the present moment. On Saturday the 30th the first eight members of the expedition came together at the Refugio de Ario. First up were a group of three Oxford Uni cavers (Vlad Turcuman, Vlad Catanea, and Fiona Zhang), keeping alive the sixty year long tradition of OUCC participation in the expedition. Following behind were Chris Jewell and his four horsemen - Mark Burkey, Martin Holroyd, Keith Chatterton and Petie Barry. The following day we got stuck right in, carting over 400m of rope to the entrance of Muxa. This we found only about 25 minutes from the Refugio by following the network of cow paths leading down the mountain.

Our first impressions were of a cave that meant business. A huge steep gully lead 40m down to the bottom of a towering cliff. I picked my way down the vegetated scree slope to the base of the cliff, where a broad shaft dropped away. I skirted around the edge to a comfortable ledge and picked up a hefty rock. I tossed it down the pitch and timed its fall. After an initial boom clattering and crashing of rocks and stones down successive pitches and scree slopes could be heard for sixteen seconds, eventually fading out of earshot. For all I knew the rock was still going, merrily bouncing down the 200m of pitches to the top of El Gran Abisu, a vast 250m deep shaft. Immediately beyond El Gran Abisu lay another shaft, a mere 105m, that would take the unlucky rock all the way to the streamway. We clearly had a lot of rigging ahead of us, but luckily Chris had packed a vital bit of kit - Martin Holroyd, who seems to be able to bolt and rig down a cave faster than most cavers would be able to abseil behind him. By the time the rest of us had finished cooling off at the lip of the doline, Martin had already placed the first of the bolts that would bring him down to -200m that day.

While Martin, Mark and Keith drilled and hammered in Muxa, the rest of us returned to the Refugio to get another 400m of rope to feed the cave's insatiable desire for 9mm Spanset.

The following day Martin, Mark, Chris and I headed underground to continue down. From the initial entrance shaft of 35m a series of small to medium pitches drop down a tall sonorous canyon like the steps of a staircase, all linked with short loose scree slopes.

At every pitch head we met rusted spits, eccentrically placed and often protruding 5mm or more from the rock. It was a catalogue of bad hand-bolting. Even by the standards of dodgy old-school rigging Muxa seems to have stood out. In Beneath the Mountains, David Rose and Richard Gregson's classic account of Ario caving, David describes a mid-80s tourist trip into Muxa on the SIE's ropes and mentions how the SIE dealt with rope rub. Often the rope was let drape over the edge of a drop, and once the rope wore through to the core the SIE would simply pull up the rope and tie it in below the worn section. Consequently there were often huge hanks of frayed rope looped up beneath rebelays.

Today saw Chris take over rigging duties. From the end of yesterdays rope he bolted down a short gully that took you out over the top of El Gran Abisu. The rest of us bunched up in the gully, having portered down a stash of gear. Chris dropped down away out of sight, the sound of drilling becoming ever more distant, his light ever more faint. After nearly two hours of inactivity we were called to action as Chris's echoing cry of ROPE FREE sounded around us. Cold and stiff we started down the rope. While the posted depth of the shaft was 250m, the gully drops you in about 50m below the roof of the shaft, so its really closer to about 300m. Underneath me the shaft plunged into darkness, beyond even the range of a powerful modern headlamp. I abseiled down some 70m and found Chris tucked into an alcove, rope and rigging gear exhausted.

Martin and Mark joined us, and with hardly a minutes hesitation Martin was back in the rigging saddle. Chris is a fine rigger, but Martin was something else, and was quickly over the lip of the alcove and out of sight, with Mark following behind. I sat about for half an hour but with the cold setting in and my portering duties done I decided to prusik out. With over 180m of shaft left to bolt below us Chris was contemplating the same, but as Martins 'rope free' shouts became ever more remote he decided to follow down the rope. Below the alcove the shaft soon belled out dramatically and became supremely impressive. Once the floor loomed into sight Martin decided to disregard the 5pm turnaround and risk missing the 8pm dinner at the Refugio. By 5:30 the team assembled at the base of the vast shaft and began the mad dash to make it up 500m of cave and across the surface to the Refugio. Chris made it in time, an impressive feat. Martin was 15 minutes late, not being able to resist popping a further bolt or two to bring him to the top of the final 105m shaft. Poor Mark was left slogging it out alone, but we saved him a plate.

Back in the 70s it probably took the Catalonians several expeditions to hand-bolt this far, we'd managed it in two day trips. As I write, Chris, Mark, Martin and Keith have entered the cave for a two night camp, to continue rigging to the end of the cave. For the rest of us, its the glamorous task of humping gear around the mountain under the scorching sun to set up the other main exped objective of C4, more on which anon.

Chris J

Active member
I’m pleased to be able to report that on Thursday 4th August, Martin Holroyd, Petie Barry and myself reached the bottom of Muxa after 3 nights underground re-rigging the 2km long streamway. The Muxa shaft series is impressive and grand but the streamway is spectacular. Camp is cosy for four people and a trip to the bottom is a ‘classic’ to be enjoyed. Next week I hope to be diving the sump and reporting back. In the meantime here is one of Mark Burkey’s excellent photos to enjoy.


  • 183C4774-4310-4496-AEF0-DE6D4B78E8C2.jpeg
    170.9 KB · Views: 275

Subpopulus Hibernia

Active member
Cabeza Muxa : A second frontline report

So, once the big 250m shaft was rigged, the next stage of rigging Muxa was to drop the next 107m shaft and establish camp at the foot of this, and continue rigging from there. Due to being vaguely ill (combination of a mild cold and heat exhaustion probably), I decided to pass on heading in to camp. It was just as well I didn't, as it turned out only four could squeeze into the tight sleeping spot at camp. So in the end, Chris, Martin, Mark and Keith headed in for an expected two-night camp.

Two days later I woke to find Keith cooking breakfast outside his tent. The underground team had run out of rope and bolts, so Keith had exited late the night before to grab some more gear and head back into the cave in the morning. And with the amount of gear needed in the cave, I'd have to head in too. So despite still being vaguely ill I got my gear together to leave. The Oxford students helped carry over the rope and rigging gear and I set off into the cave, with Keith still kitting up on the surface. As deep caves go, Muxa is remarkably easy, just one rope after another down a series of big shafts. Our lovely new 9mm Spanset rope was clean and incredibly fast, needing a few wraps around my leg to ease my descent. I finally got to experience El Gran Abisu, the huge 250m shaft that made up almost half the entire shaft series. The first 70m or so drops down to a ledge, where its briefly possible to put your feet on terra firma. But straight away you're back hanging in the harness, as you drop the seemingly endless 180m section that brings you to the bottom. After a while the depth of the shaft simply becomes an abstraction, the shaft just disappears into the gloom above and below. At the bottom a brief walk brings you to the final 100m shaft, dropped in two airy free-hangs of 50m. The lower half of the shaft bells out impressively, and this you realise is the stream passage itself, a 50m tall canyon stretching off in either direction.

It was at the bottom of this pitch where I met the camping team, waiting impatiently for the gear to arrive. Chris and Martin grabbed a huge tangle of hangars and maillons from my bag and dashed off to the rigging front. Mark hung about at the bottom of the pitch, waiting expectantly for Keith to arrive. He'd used up all his camera batteries the day before and was heading for the surface, but waiting about to avoid meeting Keith coming down the ropes.

After a while Mark grew too cold to wait any more and decided to head off. I climbed off up to the side to sit and wait in camp, which was located just below the ropes. An hour rolled by. Then another.
Eventually I decided that something must have happened to Keith to prevent him coming down, and I'd have to head on alone. I had just picked up a 100m rope bag and was about leave when I shouted Keith's name up the shaft one last time. unexpectedly, his voice boomed back down the pitch.

Soon his light appeared, and I sat and waited for him to appear. When he arrived he explained that he'd yanked his thumb at the cave entrance and almost didn't come in. He'd only come in because he was carrying my camping kit, which he knew I'd need. But he'd had to ditch 100m of rope and 10 bolts/hangar sets at the entrance. We'd have to pray that the gear in the cave would get us to the sump. I left Keith at camp, picked up the 100m rope bag and headed off down the passage.

One short rope pitch later and I hit the first of the many wet bits. This was knee deep, but there was waist deep sections further on. Short splashy pitches followed in quick succession, with turquoise pools at their bases. The passage soared high above me, 50m tall or more, and 4/5 m wide. Some bigger pitches were passed, then noisy traverses over crashing waterfalls. It was a superb bit of passage, but it went on and on and on, pitch - lake -pitch - traverse - pitch - climb - pitch. There was 25+ pitches to negociate, 2km of passage and 300m of depth gained, all done soaking wet.

I kept expecting to see the lights of Chris and Martin ahead of me, but nearly two and a half hours of fast caving had rolled by before I caught up with them, in the midst of rigging a 15m pitch, the final one before the sump. My arrival was well timed, they'd only just ran out of rope and were about to start packing to leave. The rope was quickly pressed into service, and fifteen minutes later we were down. One short climb later and we were on the last 150m stretch of streamway leading towards the sump. We hit a deep pool where the passage bent around a corner. Martin did some Spiderman moves clinging against the wall to vanish around the bend and report back as eloquently as a Northerner can - "There's the sump, and its fuckin' beau-tiful!

Job done. Cave rigged. 600m of shaft rigged, followed by 26 pitches spread over 2km of streamway. Nearly 1300m of rope had been used, and 180 bolts had been placed over four long days. We made it back to camp three hours later, where Keith was waiting with a hot brew for us.

Camp was tight but maneagable, basically it was on a false floor of boulders wedged high up in the main streamway. There was room for four campers, and a small kitchen / changing area, but no latrine - this meant abseiling two pitches, not ideal first thing in the morning.

We woke and sat about drying our sleeping bags while cooking breakfast - despite two tarps the drips were finding us and our sleeping bags were damp. Martin kept making unfavourable comparisons between Chris and Ken Pearse, having apparently been denied a chocolate bar at one point by Chris and being told to keep rigging, but despite this grievance our campsite was fairly cordial.

Finally we packed up and started the prussik out. The first two 50m free-hangs were a bit of a pig, but above this the climbing was fairly smooth. Around 3 hours later I surfaced to baking aftermoon heat. Phase 1 was complete, on to Phase 2, the diving.


Active member
Not sure if I'd be happy or perturbed by my expedition management being compared to Ken Pearce, but you can't argue with results.

Chris J

Active member
On Monday 8th August Rich Hudson, Tom Chapman, Keith Mason, Phil Baker, Sam Lee and Shane Diffley entered the cave with 6 bags of diving equipment plus personal camping kit. 4 bags made it to the sump and 2 bags were dropped off part way. Tom and Rich exited whilst the other four camped overnight. On Tuesday 9th Chris Jewell, Lisa Wooton, Stu Weston and Mark Burkey entered the cave with a plan for Chris to dive the sump.

After some delays passing the exiting team the dive group reached the bottom of the shaft series and camp. Here comms to the surface we’re established on the newly installed Nicola radio. The dive team headed off along the 2km stream way which drops 300m via 26 pitches to the sump. About half way the additional kit was picked up and the four heavily laden cavers plodded on slowly. Unfortunately 20 minutes later disaster struck. Mark was approaching a pitch head when the belay the traverse rope was attached too broke. Mark fell forward on to his face with his nose taking the impact. A lot of blood followed and it was clear he’d broken his nose. Everyone fully expected the trip to be turned then and there but Mark was determined that the dive would go ahead and that he’d be there to document it.

Several hours later the team arrived at the sump. Chris prepped his dive gear aided by Stu and Lisa whilst Mark prepared to photograph the effort. However when he unpacked his camera he discovered to his horror that his fall had damaged the case and caused it to leak. The precious camera was flooded and no photos would be possible!

Whilst the team kept warm in a storm shelter making hot drinks Chris entered the water and began his underwater exploration. The excellent visibility he’d expected was reduced by the moon milk sediment that kitting up had disturbed. Underwater large moon milk deposits hung to the walls in lumps. With little else to belay the dive line to Chris wrapped the string around these sending little puffs of sediment into the water. The floor and walls of the sump were strewn with old dive line from Ricks dive in 84. Chris dodged the hazardous old line and pushed into new territory at 30m depth. Visibility got better but the way on wasn’t obvious as the passage twisted and turned going up then back down again. There were precious few places to belay the line in the clean washed sump. After about 150m the sump began to trend upwards. 5m later Chris was at -15m in the bottom of a steeply ascending shaft. With nothing to secure the line to he spooled out line whilst rising up. At -8m depth the reflective surface above became visible. Taking it nice and slowly he reached the surface where a tall slim passage led away from a circular sump pool.

After dekitting Chris headed along the new cave passage. However only 15m from the sump pool the next obstacle was found. A short pitch with the whole streamway crashing down filled the passage. Although the pitch wasn’t more than 2m, the floor and walls were smooth moon milk with absolutely no foot or hand holds. Knowing there was no safe way down Chris turned back. He surveyed back through the sump and returned to the waiting cavers.

The rest of the team had kept warm and well fed but everyone was getting tired at the end of a long day. After packing everything away the team finally left the sump at midnight. A very very slow return to camp with heavy bags was made with Chris and Mark reaching camp at 4.30am and Stu and Lisa at 6.30am.

No one wanted to get up early but by midday we were awake and eating breakfast. The Nicola radio was playing up but we understood that four cavers were coming in and so we planned our exit. Many slow hours of prusikking later the surface, food and beer was reached!


Good effort everyone! Sounds hard-won progress!

I take it you'll be back with a drill in a dry-tube to rig the next pitch and continue exploration?