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Drunken Horse Hole

Drunken Horse Hole at surface

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Poul Eich Oíta



M 10254 x 03638

510224 x 703671

84 Metres

6 Metres

5.6 Metres




Where the coast road, (R477), encounters the coast at Poulsallagh, (west of Ballynalacken castle), it turns north passing an area where visitors park to enjoy the broad ocean and landscape vistas; it continues north passing a series of low cliffs. Two kilometres, from the parking area, the cliffs reduce in height forming a series of limestone terraces. The parking place is a hundred metres down the hill on the right hand verge.


Located twenty five metres above, and two hundred metres south-east of the parking place, on a bearing of 154°Mg. The route ascends four terraces each diminishing in height on approaching the large gulley. These extensive cliffs delineate the upper geological formation of  Knockauns Mountain.  The uncompleted dig of Poulcaherdhuin is a further four hundred metres to the ESE at an elevation above sea level of one fifty metres;  height differential between the two sites is some seventy metres. It too is an example of truncation.



The chronological record below briefly outlines significant events. Detailed information may be found among the Pegasus Club Nottingham website Blog entries, or among members personal log books.

2015. 27th December: Upon descending the western side of Knockauns Mountain, having visited a souterrain within the ringfort of Caherdoon, (Westropp, 1999, p123), NB and PC emerged onto  the lower terraces of the broad limestone terrain. Near the north-western end of the large gulley a subtle water worn feature was identified having formed in the edge of a shallow limestone terrace. Postulation took place regarding the possible hydrological relationship of the area to Cliff Cave.

2016. 9th January:  Removal of turf and shrub exposed a well defined pot, its truncation suggesting pre-glacial origins; Midlandian, or even Munsterian. The initial debris content consisted of a thin layer of dark top soil with a coarse light beige clay-gravel immediately beneath. At differing depths within this pale deposit various sized boulders emerged, several in excess of one hundred kilograms. Their shape is mostly angular with only two of the larger exhibiting evidence suggesting being water rolled.  

16th January: Having long intended to prospect the area permission had been previously sought, and eagerly granted, by the owner, JC, a good friend of Pat's, to wander at will. As the mountain is grazed and regularly walked by the public a fence was erected enclosing the opening within an area of eight by five metres: an unequivocal demonstration of respect and appreciation.

3rd March: Tractor tyres and concrete lintels carried up, result four exhausted individuals.

4th March: Hauling tripod frame erected and secured.

7th March: Concrete lintel support for tyres installed.

26th March: Three metres of depth obtained, formation and fluting considered remarkable.

3rd April: Access steps installed vertically down northern rift.

21st April: Much of the bottom of the pot found to be solid.

25th April: Entire base of pot exposed. It is a blind pot; five+ metres deep. 

2nd May: Pot found to be flooded to two foot depth; excavation of northern rift commenced.

12th May: Excavation work along northern rift concluded; southern rift commenced.

23rd May: Excavation work along southern rift concluded; closure of dig reluctantly acknowledged.

1st July: After much thought of "where has the passage gone" the theory is that the pot is the remains of the very base of a pot, a sump as it were, that was formed by water falling from a height; the downstream and upstream passages long since erased by successive glacial erosion. Balcombes Pot, Coolagh River Cave, appears such a formation; itself a blind pot some five metres deep formed by turbulent water cascading into the pool to then drain away along the main passage.

2nd July: Photographic recording commenced, water depth of two feet appearing stable.

4th July: Commenced clearing site of digging equipment prior to reinstating the area.

12th July: Site cleared. Ladders remain in pot to accommodate survey.

!5th August: Survey completed.


22nd August: Concluding trip to retrieve ladders for immediate use at Considine's, Poulnagun.

Drunken Horse Hole Dig

Matt Randall steadying a kibble on it's way to the surface

Drunken Horse Hole Dig

Pat Cronin using the steps to descend the pot



Concerning the possible relationship between Poul Eich Oíta and Poul Aillte.

The townlands of Ballynahown, Ballyryan, and Crumlin have been subjected to increased scrutiny following the discovery, and exploration, of the latest "Green Hole"; Cliff Cave or Poul Aillte. Dived for one thousand metres to surface in a wide streamway pushed for  two kilometres to an obstruction within the low bedding, JW, supported by MM, (2015). The present end of the bedding plane passage, (January 2016), is estimated as 700/800 metres south of Poul Eich Oíta. It is possible, if the survey data is accurate, and the intervening geology kind, that the surrounding catchment area may have contributed significant drainage potential toward the development of Cliff Cave, (Poul Aillte). Poul Eich Oíta or another adjacent site may well provide an alternate, more accessible route into the system below, at an estimated depth of eighty metres, rather than negotiating entry through the unpredictable marine entrance located at the base of a cliff facing west into the Ocean.


Archaeological implications regarding the discovery of stalagmite within Cliff Cave.

Cliff Cave was formed by the action of fresh water draining from the area of Knockaunsmountain, not by marine erosion. Today, 2016, the entrance is approximately ten metres below sea level; dependent on the state of tide. The passage floor inside the entrance drops slightly then levels off. Extrapolation of the present cave floor level out to sea provides an approximate location where the ancient coastline once meandered, suggesting a distance from the present coastline when the cave was formed of up to one kilometre. Of note is a submerged stalagmite located some six hundred metres from the entrance of Cliff Cave at a depth of around eight metres. This stalagmite could not have formed under fresh or salt water therefore it must pre-date the period when the cave became permanently inundated. This substantial piece of stalagmite boss would, if successfully examined, provide a date when it formed, and so offer an indication of the period prior to which Cliff Cave developed. In turn this date would be invaluable to offer shape to the earlier coastal landscape, possibly during the Mesolithic period, (5500 - 4000BC). An entirely different piece of stal was found broken nearer the entrance, (2014), and is awaiting examination in Bristol, (2016); it  appears  somewhat decayed. There are presently, (2012 - 2016), ongoing archaeological excavations uncovering evidence of Mesolithic activity along the coast from Fanore south to Doolin, These sites would benefit enormously with a clearer understanding of where these sites were in relation to the contemporary coastline; though a precise sea level in relation to the coastline remains wholly dependant on the dynamics of Isostatic movement.

Isostasy / Eustacy; associated effects.

Broadly defined; Isostasy is the gravitational equilibrium relationship between a land mass and presence of an Ice Cap. Upon formation the increasing weight of the ice cap presses down upon the land mass, as the ice melts the land mass "floats" back buoyed up by molten magma underneath: Eustasy relates to the uniform depth of the ocean/s.


Evidence of past glaciation is present throughout the Burren. Most obvious are the isolated boulders, (Glacial Erratics), extant on the limestone karst. Further evidence,  in the form of smaller erratics, are found underground. Several examples have been found in Drunken Horse Hole; of interest are the many hundreds found, and continuing to be found, along the stream passage of Fraggle Rock.

Erratics in Drunken Horse Hole, (Poul Eich Oíta)


Digging thus far, (March 2016), has exposed a beautiful, vertical pot measuring three metres in length by one and a quarter wide. Several small rounded examples of erratic were found among the initial upcast debris, as the site was being cleared; no accurate provenance of context or depth is therefore attributable.  However, at a depth of two metres more erratics were encountered. The first within a dry, stiff clay by AB, (11th Feb 2016); the largest  six inches, (150mm), in diameter being predominantly white/cream with black grains throughout. A second group was unearthed by PC, (15th Feb 2016), among an area of angular stone debris in the southern area of the pot, also at a depth of two metres suggesting contemporaneous deposition, their appearance being similar to each other. A wide variety of erratics, some indeed similar in appearance to those at Drunken Horse Hole are to be found within Fraggle Rock located five kilometres to the south-west. 


As close as can be determined from available data the two glacial episodes referred to above are,
Midlandian Glacial maximum, estimated as 80,000 - 13,000 years ago (Mitchell & Ryan 2001, 61)
Munsterian Glacial maximum, estimated as 300,000 - 130,000 years ago (Mitchell & Ryan 2001, 68)

4th June 2018 log


=    Nigel Burns
=    Aileen Byrne
=    Cheg Chester
=    James Callinan (Land Owner).
=    Pat Cronin
=    Michael Marek
=    Jim Warny


Mitchell. F & Ryan. M, 2001    Reading the Irish Landscape,  Town House and Country House, Dublin.
Westropp TJ, 1990    Archaeology of the Burren, Ed. Comber  M. Clasp Press, Ennis. 

PC 2016

Drunken Horse Hole Survey
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