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Tunnel Cave - South Wales

Graham Wilton-Jones

Buckett and I recently visited this fine system, and I felt it would be useful to offer a brief description in the BB, since 'Caves of Wales and the Marches' is rather inadequate and, perhaps misleading.

The location can be found on the 2½" O.S. map, SN 81, at SN 837165, but this map shows and the book description mentions a path from the Haffes.  This path no longer exists, but one starts from the Dan yr Ogof caravan site, past the sheep pens, to a point overlooking the Haffes, and thence onto the path leading over the moor towards the Giedd.  The path follows a wall to the left until it has climbed up the steepest section of the hillside, and then divides.  One part continues beside the wall running towards the dry valley above Dan yr Ogof, and the other branch turns sharply right towards Waun Fignen Felen. From this junction one does as the book says, almost, climbing up to the high point on the right, on the edge of the hillside. The top entrance of the cave is practically on the highest point - a most unlikely place for a cave.  In BCRA Transactions Vol. 4, Nos 1 & 2, March '77 is a surface survey of the area with cave surveys superimposed; including Tunnel.  The location of the top entrance is easy using the lines of shakeholes and the nearby dry valley.  Approaching the entrance even quite closely the only evidence of cave is a low pile of bang debris.  The entrance cover is only seen when you are right on top of it.

The entrance shaft is virtually all mined, square section at the top and spacious, and is 35 feet deep.  A 30ft ladder belayed directly to a railway line at the top is sufficient, the bottom of the shaft being narrower and climbable.  12' down there is a firm railway sleeper platform all round the shaft.  At the bottom the pitch breaks into natural rift at the Courtyard pitch.  After a short piece of horizontal passage, a bolt above and exposed ledge takes a 25' ladder into Cascade Aven.  The Second Cascade (the system was explored from the bottom) is a steep, stal slope littered with bang debris, steepening further until it finally overhangs the First Cascade, which comes in from the other end of the rift.  I found a handline useful on the Second Cascade, descending to the Wire Traverse on the right (looking downwards) having belayed to a eyehole in the right hand wall.  This required about 60' of handline, but 120' as the book says is needed if it is belayed at the bottom of the Courtyard.  The wire on the traverse is fixed, and I belayed 100' of handline to the bolt on 'the far side".  This was also far too much, about 60' being sufficient.  However, this First Cascade is steep smooth, and the handline here is invaluable.  Leading off from these avens are a few passages which constitute the Cascade Aven Series.  At the bottom of the stal slope, the rift is choked up with gravel and and stal but a small draughting passage is the route on downwards.  A twisting hands and knees crawl leads to a couple of 15' climbs down. After the first climb the passage enlarges.  At the bottom of the second is the way into Paul and Barnabas, concealed between the boulders and the wall.  This is the passage leading to the numerous pearls.  Ahead the route continues down to a sandy chamber, but the way on is a climb up just before this.  The passage is now a winding rift dipping at about 10°.  By traversing horizontally we ended up in the roof tube, and this is the obvious place to be for route finding since the draught here is dispersed.  There are one or two places where the passage is too wide to traverse, and it is necessary to descend and climb up again on the other side, but the route is not as complex as the book would have us believe, nor is any of the cave technically difficult.  Normally wherever a decision has to be made the wrong route is a cul-de-sac, and the draught can occasionally be felt. Eventually a stream is reached and soon after is the grille with the show ' Cathedral Cave' beyond.  It would have been possible to have the key for this grille, but we had to collect our tackle from the top anyway, so there seemed to be no point

Returning up the passage the first major opening on the right is East Passage.  This is much easier than West Passage, the route to the top entrance.  Cross Passage on the left starts as walking but soon degenerates to a crawl over sand to emerge in West Passage.  East Passage continues, passing the way to Xmas Grotto on the right, up a climb into a large phreatic tube and into the high Steeple Aven.  We did not continue here, but the passage goes a little further to reach Final Chamber.

The whole of our trip took four hours, during which we covered much of the cave twice - in and out. Next time we shall rappel in, visit Paul and Barnabas and Xmas Grotto, and leave via the show cave beside Dan yr Ogof.

Useful references:

BCRA Trans. Vo1.4, Nos 1 & 27 Mar, 77.  (Survey p.296, plus several other notes)

Caves in Wales and the Marches, 167; .o62


CRG pub. No. 7

Ed. note: I hear, through the Mendip grapevine, that a new Welsh caving guide may be underway.