The Discovery and Exploration of Poll Dearg


Townland: Cahermacnaghten
Grid Ref: Clare 9, 29.5 E / 49.6 N
Entrance Alt: 174m
UBSS Code No: C21
Approx Length: 800m (527m surveyed, 250m estimated)
Approx Depth: 60m

History of Exploration

The University of Bristol Speleological Society have spent several weeks every year since the late nineteen forties exploring and recording new sites of speleological interest on the Burren in County Clare, Ireland. During one such sojourn in 1960, Prof. Tratman and four other members of UBSS spent some time examining several interesting sites along the Knockavoarheen Ridge. This east-west running ridge, about 3 miles north of Kilfenora, marks the point at which the gently southward sloping limestone meets the over-lying Glare shales. Many small streams running north over the shales go underground when they meet this boundary. The largest caves found in the area are Poll-Cahermaan (C6), Poulawiliin (G2) and, now, Poll Dearg.

On July 12th 1960 eleven sites were examined, one of them, Poll Dearg, being assigned as code number G16. It was given only a cursory surface examination and the following appeared in the UBSS log book:

"In a field wall about 30ft north of a valley an orifice 3ft x 2.5ft gives a vertical rift 15ft deep running E-W. Recent fall of roof over rift probably led to the formation of the oriface. Choked to the east but possibly passable under this obstruction. West end of rift could lead down through boulders going to the left. Well worth a trial."

On July 14th a return visit was made to the more promising sites along the Knockavoarheen Ridge, most of which were descended. Three members of the visiting UBSS group entered G16 through the surface collapse mentioned above and the following was recorded:

"Initial drop of l6ft to stream through dome of very loose jammed boulders. Downstream: Passage 18" wide & l5ft high followed for some 40ft until partially blocked by flowstone on the right hand wall. An attempt was made to pass this in the roof but although the passage is rather tight it is probably possible to pass over the flowstone and drop into the passage again; the return journey looked exceedingly difficult.

This may be passable by a small person armed with a hammer and chisel. Upstream: This section was not surveyed but after passing a blood red mud formation on the left hand wall, (a similar substance to Bloody Guts in Cullaun 2) which had to be gouged away by the hand. An aural and visable connection can be made with the surface in a small swallet hole about 60ft south of the entrance."

No more references to this cave have been found until, in a section from the UBSS log book of 1975 listing all of the known sites along the Knockavoarheen Ridge, this extract seems to refer to the same cave:

"14m east of marked wall and immediately south of boundary of field is Badger Hole Swallet. Might go with digging but a lot would be needed. Very small collapse (lm in diameter) at 20m south of track on line to swallet may connect to cave."

This description from 1975 was clearly a lot less optimistic than that of 1960 and no further exploration by UBSS seems to have taken place since they changed the name from Blood Hole to Badger Hole Swallet.

Further Exploration - 30th December 1987

A combined trip organised by Croydon C C and the University of Kent Troglodytes visited the Burren over the New Year just gone. Those taking part were Nigel Clarke, Eric Downer, George Pankiewicz, Martyn Pickering and Paul Stacey. The group decided that one of the days ought be spent exploring a hole with potential for extensions rather than just doing tourist trips. After much searching through Caves of County Glare, two caves on the Knockavoarheen Ridge were selected these were Poll-Cahermaan and Poulawilljn. Poll-Gahermaan was chosen not so much for its moving mud banks or boring monotonous narrow streamway but more because none of the group could face the prospect of crawling through the "smelly, black, leech infested mud" in Poulawillin.

The change in the pouring rain and the subsequent, predictably fruitless, search for Poll-Cahermaan had us all thinking after several miserable hours that leeches might not be all that bad to crawl through. Several possible entrances e to the mythical Poll-Cahermaan were opened up; all to no avail. d Two entrances were exposed big enough to let someone through. e On both occasions I was selected to have first go. My colleagues must have a very low opinion of me since in one entrance I was in danger of being buried alive and in the other I refused to show off my ferreting skills whilst lying head first, down a slippery slope composed of decomposing cowsh! Of the all the holes I have encountered this was quite definitely the smelliest I have ever come across. After about three hours Martyn, Eric and I slopped back despondently to the minibus leaving George and Nigel to scour the hillside for the entrance that the farmer seemed to have filled in.

During George and Nigel's reconnaissance a small stream had been seen and traced to a hole between boulders in a swallet that appeared to be right on the limestone-shale boundary. After spending a few minutes moving boulders aside a gap large enough to enter was made and they descended into the swallet. Almost immediately underground a low streamway was revealed which continued downstream for about 60ft to a boulder blockage. In this section of passage a red mud constriction on the passage walls had to be squelched through leaving the pair with a coating of disgusting crimson-brown goo over their wet-suits. The boulder blockage took a little more time to clear but with a bit of squeezing the two passed this obstacle and continued for a further 12m to where a climb up, over a calcite flow, ended when the passage got impassably tight. Above this final point the inscription "UBSS 1960" paid witness to the fact the two had rediscovered a cave that had thwarted previous attempts to access the passage they could see beyond.

After returning to the very snug Doolin Hostel for dinner, the guide books were consulted over food and wine. The position of Poll-Cahermaan was still no clearer than before. More interestingly though, the "unknown" swallet that George and Nigel had been into could not be identified.

Hangover Cure - 1st January 1988

Despite feeling decidedly rough after the night before's celebrations it was decided that this intriguing site deserved one last push in an attempt to get at the cave beyond. Not having come to Ireland with any real intention of finding new cave we had to improvise digging and surveying gear. The sole piece of digging equipment we possessed was a Petzl bolting hammer and our surveying kit consisted of a Silva compass with a "calibrated" knotted piece of string as a tape measure. Eric, George, Martyn and Nigel surveyed the passage up to the final calcite blockage whilst I spent a desperate two and a half hours attempting to enlarge the narrow passage just beyond the UBSS graffito. The constriction was high enough for me to almost stand naturally, but its meagre 18cm width was insufficient for me to turn round in. Progress was made by attempting to knock off any nodule that appeared to restrict my arms or legs so that it would eventually be easier to adjust my position to assume a better attacking stance. As much as I hate admitting it, I gained a great deal of perverse satisfaction seeing straws hurtle down the passage as I gave them an almighty whack with the bolting hammer. After almost three hours work I had just reached a position over what looked like the widest section of rift, ready to descend back into the beckoning stream below. I had moved less than 2m up the passage during all that time. Nigel had by now appeared and gave me some welcome encouragement and advice during the final 30 minutes of digging. The survey had now finished and the two of us decided that we would give the dig another 30 minutes before exiting. Eric, George and Martyn returned to the minibus to await our report.

As stated in the 1960 UBSS log book, the return up the rift looked rather nasty and I was not fully convinced that I could do it. After a quick chat with Nigel I studied the widest part of the rift and gently squeezed and wiggled my body down the rift. Sooner than I expected I was standing on the other side of the blockage with a small streamway leading away before me. Yelling jubilant noises at Nigel, I proceeded down the narrow twisting streamway until I finally came to sharp right hand constricted bend. Edging around the corner I was greeted by a large hole with the water shooting into the blackness in front of me. Initially I could not see the bottom and had to re-adjust my position to get a proper view. Even though the pitch was eventually found to be only about 7m high my first impression of water hurtling into a bottomless void still stays with me. Returning to Nigel, I managed to guide him down the rift before going and having another look at the pitch.

Reversing the squeeze was much easier than expected and we sprinted back to the others who were changing at the minibus. Grabbing the rest of the bolting kit, an SRI rope and some personal tackle Nigel and I hurriedly returned to the swallet.

The squeeze did not seem quite so hard the second time we went through it; the psychological barrier is often the worst enemy at pushing new cave. Two bolts were placed, albeit not very well, at the head of the pitch. Rigging up in my SRI gear I had a great feeling of anticipation of what lay beyond. (Or was it the fact that as I was so excited I was desperately holding off the need to go for a wee now that I had all my SRT gear on.) Descending to the bottom of the pitch I was relieved that the plunge pool was no more than knee deep since I am not a very good swimmer.

Stumbling off into the passage I got a chance to gaze round at the pitch. The chamber I was standing in was really a double aven with the stream coming in from the western side. a Another inlet also entered the aven from the northern side through a bedding plane too tight to even contemplate digging. to All over the floor of the eastern end of the aven was a soft, as pure white calcite covered mud floor. Initially, when I by scanned the aven, I could not work out where all the water was my going. On closer inspection of the southern end of the chamber my I saw that a small continuation of the streamway headed away I west, probably passing under the pitch. Yelling back up to se Nigel I told him what I had found and then I started following the streamway down the passage. Faster and faster I seemed to go as at each corner the noise of the stream disappearing into the hill beckoned me on. Throughout it was quite obvious that he the entire 70m of passage was totally untouched by human hand. I was certain that this had to be virgin passage as near the point where I reluctantly turned round to go back to Nigel several lm long straws hung right down to the streamway. After ascending the rather wet pitch the two of us returned to the others who were now concerned as to why we had been so long. They understood completely once we had recounted our story.

That evening we drank in O'Connor's Bar in Doolin, along with about 25 other British cavers including Charlie Self the compiler of Caves of County Glare. We declined to tell them why we were looking so smug. They knew however that we had been digging in a promising site even though they did not know where. Despite this the BEC were generous enough to offer us the use of a decent surveying kit if we arranged to pick it up the following morning.

Follow That! - 2nd January 1988

Strangely, the next day none of us had problems getting up several hours earlier than usual. A large lump hammer was purchased in Lisdoonvarna so that the squeeze could be widened further as certain larger members of the group would not be denied access to the promise of more passage. Most of us passed the squeeze with no problems but George was unable to get through it as it stood. I don't know what he did to it exactly but the squeeze really isn't there anymore. From the reports I've heard, George's determined ten minute digging session probably had more impact than I did in three hours! The pitch was re-rigged and a ladder replaced the SRI rope. Everyone participated in the grade-3('ish) survey as we made our way into the unknown. This was the first time that any of us had pushed any real length of virgin cave passage and we all agreed that surveying in was probably the best way of exploring, as well as being the most sociable. It gives you just the right amount of time to savour the cave and wonder what really is around the next corner.

The passage from the base of the aven was around 200m long and contained many pure white calcite flows and curtains. Many of the formations obstructed the passage once again proving this had to be a new find. Near the passage end a major inlet joined the streamway and a watery climb down into a rift chamber marked a sudden change in the passage character and direction. Following this fault line the water passed through a narrow fissure in the floor and shot into a large void below. A dry by-pass to this was quickly found, following which another obstacle succumbed quickly to the wrath of the lump hammer. Past this squeeze another pitch, estimated to be about 6m deep, was encountered landing in a large chamber with several possible ways going off from the bottom. This was a complete surprise; we had been expecting either another squeeze to be by-passed or worse still a sump. The Burren is a caving area with few pitches and to find another pitch so soon left us completely wanting after the bolting set, a few ladders and another day in Ireland, for this was our last day. The second pitch consequently marked the limit of exploration (at 290m length and about 25m depth) of the cave at that time. All the group vowed to return at Easter.

Naming the Cave

After much discussion it was decided that the new find should be named Poll Dearg in an attempt at a rough Irish translation of the original 1960 UBSS name, Blood Hole. Sheila Bunce suggested that a more literal translation of Poll Dearg is Red Hole. This is still an acceptable name since the "Blood" in the original name was merely a poetic description of the red limonite deposits found near the cave entrance; Red may be more prosaic but is still accurate.

Easter Exploration 1988

On the strength of the what had been found over the winter, ten people from both Croydon C C and Uni. Kent Trogs decided to spend Easter on what was sometimes referred to as the "The Blood Holes Expedition", to push Poll Dearg to a conclusion. The original plan was for us to spend over a week on the Burren at the Doolin Hostel but, due to a double mini-bus booking beyond our control, the trip was reduced to just five actual caving days.

Five Go Caving A gain

Trying not to think of what Ghar Parau was in Irish the original five explorers Nigel Clark, Eric Downer, George Pankiewicz, Martyn Pickering and Paul Stacey returned to the un-descended pitch 29Cm into Poll Dearg with a large assortment of rigging tackle. Whilst bolts were impatiently hammered in above the 6m pitch, Chris Grimmet, Chris Fry and Richard Rolf followed up the rear taking photo's where the narrow canyons and the squeezes permitted. The pitch was descended and a 10m wade through knee deep black mud led to a further lm drop into the continuation of the fault passage ending in a small, chert constricted, hole with blackness beyond. The chert peeled away from the limestone bed with just a few knocks from a big lump hammer. As the first layer was being knocked away ominous booming noises started to be heard from the other side of the constriction. Once the hole was wide enough a large rock was hurled through the gap and a large crash floated up out of the depths over 2 seconds later. More digging ensued and, after the placement of several bolts, the last 55ft of ladder the group had was fed through; down into the what was quite obviously a large chamber. The ladder was descended and the life-lining party were treated to a glimpse of a big open pitch yawning below them. Two of the party, Eric and George, were even more impressed when they both returned with separate reports of the ladder not reaching the bottom by about 6m. There was nothing for it but a return visit would have to be made the next day. As the group made their way out there were many mutterings along the lines "It's not fair" and "Play the Irishman"!

Once More into the Breach

Despite the weather being decidedly nice outside and the cave seeming to be tighter and worse than most of the group could remember, the original explorers carried yet more tackle the top of this new pitch. (As a measure of the narrowness of the cave, it took well over an hour to travel the 300m to the top of this third pitch.) Unfortunately, due to someone not shrinking the new SRI rope I had to carry in all 80m of 10mm Edelrid rope. The bag was considerably wider than me in most of the squeezes! Rigging the new pitch with SRI rope involved a lined traverse out over the top of the pitch to a third bolt placed so as to clear the multiple ledges below. Before descending the 23m pitch a short session of gardening had to be indulged in as the traverse and the take-off point seemed to consist of nothing more than anti-gravity chert.

The chamber at the bottom of the pitch seemed to be the end of errosion on the fault-line with the water draining away down an unpleasant looking passage on the western side of the chamber. Unpleasant though it was, this looked encouraging as the passage, although smaller than before, seemed to be heading south-west again. Joking to the others as they landed in the large chamber below the pitch someone was heard to comment, "it's alright it looks as if it's going to sump fairly soon". This proved to be a particularly mistaken comment.

Along the entire length of passage the dimensions rarely exceed lm by 0.7m and through-out the 500m that was explored sadistic chert nodules and razor sharp limestone plates, often covered with sticky brown mud, made the going difficult. The end of the cave widened out as the roof dropped; we eventually retreated after the passage started to disappear into a very wet bedding plane duck. I doubt if the cave passage continues much beyond this point. Throughout its length there was much evidence of flooding debris and lumps of foam were seer decorating the roof in the last 200m. It seems that the expedition members, despite wingeing about how warm and sunny it was on the surface, were indeed fortunate to have water levels that were so low. The most redeeming feature (depending on your point of view) of this last piece of appalling passage was the huge quantity of frogs we found in it. From about half way down its length the occasional reptile was seen but near the end the sheer number of these, rather pathetic looking amphibians caused us all to take evasive action so that we did not crawl over them. Frogs had to be picked up and placed on the ledges as we neared them and, at one point they even had to be passed back down the line when we ran out of ledges to use. At the end of the passage there is still an account of a watery constriction infested with squirming frogs yet to be verified! One lonely newt was also discovered on the return journey.

The Final Trip

People's enthusiasm and wetsuits were wearing decidedly thin when, two days later, the inevitable call went out for a survey to be done. Nigel and I, with Chris Grimmet photographing the big pitch, descended first and commenced the survey in the passage, now named "Frog Street". This name seemed rather apt not only because of its inhabitants but also because its ghastliness was on par with Frig Street in Darren Cilau. A much disillusioned non-surveyor in the form of Colin Bunce caught us up at the pitch. He raced down Frog Street to explore the delights beyond despite the considerable amount of sniggering which followed after someone had asked him if he "liked frogs legs". When he eventually returned covered in mud, a single word summed up his appreciation of Frog Street, "Horrible!" And with that he was never seen again while we were in Ireland. (Sorry Colin we'll try to find more attractive looking reptiles next time.) The original plan was to survey the entire length of Frog Street but because of the confined space and the effect of too much Guiness on my bladder we had to stop with only about half its length covered. Other catastophes hit Eric, Martyn and George as they attempted to survey out from the big pitch. These included: disintegrating wetsuits, shredding oversuits, flesh wounds appearing and instruments fogging up.

The Survey

Although one aim of the expedition was to produce a high quality survey the cave got to us before we managed to finish it properly, despite some people spending a total of 25 hours down Poll Dearg over three days. Perhaps a better survey Would have been possible were it not for the fact that the team had so few caving days on the Burren due to time problems mentioned previously.

The survey was carried out using a Suunto KB-20/360R compass and 60m Rabone Chesterman Fibron mining tape in the lower (Frog Street) passage and Suunto Compass KB-14/360R, clinometer PM-5/360PC and 30m Rabone Chesterman Fibron Tape in the upper (entrance) passages. The resultant data was computed in Ireland using programs written in BBC BASIC by George Pankiewicz run on a BBC microcomputer. This produced both plotting co-ordinates etc as well as an on-screen line plot of the cave, the scale of which could be varied before printing off. (It was also very good for impressing other cavers in O'Connor's Bar).

The total length surveyed was 527m in 171 survey legs. Of the unsurveyed section the first 60m was measured by just running the tape out to its full extent, the rest is an estimate by the few people who have been to the very end. As stated above we had problems with the instruments in this difficult cave, particularly with the clinometer. This led to heated debates about the accuracy that we could claim for the survey. The purists pointed out that Brian Ellis in Surveying Caves (BCRA,1976) states that even for a Grade 3 survey "The use of the clinometer is recommended as it will improve the result and should definitely be used when surveying cave passages which have an appreciable slope." The counter-argument was that, with an average leg of 3.lm and ensuring that the tape was "stepped" (ie. kept level) between stations, application of the cave surveyor's bible gave a misleading impression of the care taken over the survey. It was decided therefore that we should publish the survey without assigning any grade to it but to accompany it with these notes so that users could decide for themselves what confidence to have in it. In our view the survey, as published in this article, gives sufficient information about the nature of Poll Dearg to enable exploration to continue and to relate it to other caves and sinks in the area. A full set of survey data is held in the Croydon Caving Club library.


We spoke to two different people in the vicinity of Poll Dearg seeking permission to cross the land. Both were happy to give this but it appears that neither was the actual owner. Our only contact with him was a very polite note he left under the windscreen-wiper of the minibus asking us not to park on the green road as it obstructed his tractor access to other fields. In view of this it would be courteous if future visitors parked on the rough ground right at the junction of the green road and the metalled road that runs N/S through Cahermacnaghten.


We are grateful to Charlie Self for providing us with the early U.B.S.S. references to the cave and to the Moloneys and Mandy, the warden at the Doolin Hostel for their never ending hospitality.


Poll Dearg is a worthy inclusion on the "tight and nasty" list of Irish caves for anybody who enjoys that sort of thing, the 23m pitch probably being one of the nicest big pitches on the Burren. Until the cave has been observed in high water further exploration of the bottom passage is probably best left to its more aquatic residents!

Paul Stacey