OUCC Proceedings 9 (1979)

Simon Fowler and Martin Laverty

A large and complex resurgence system in an extremely impressive position. Most of the passage is dry, but flooding could be serious. There is evidence of previous exploration, but no details are known to us. Some very interesting and pleasant passages are to be found, along with some less attractive ones. There would still appear to be some potential for extensions, especially by climbing rifts or, of course, sump diving.

The Rio Casaño gorge must be descended from the Buferrera-Belbin track which takes you over the Belbin moraine and then deteriorates to an imaginary line on the map. From here aim roughly north for about 400m to a col between two small peaks - this gives an imposing view of the gorge. Descend a bracken covered slope, avoiding Urogallo birds, to a gap in a dry stone wall and a shepherd path. The heads into the steep sided valley to the west as opposed to the potentially more rapid routes straight ahead. Then simply (!) follow this steep, stinging nettle infested slope down to the well wooded valley which the shepherds evidently use for their supply of firewood. The entire river, at this point in the gorge, originates from El Hoyo la Madre so the cliff, if not the actual cave, is easy to find. Water gushes out from several points in this cliff face, aligned along a steeply inclined fracture. The entrance itself is not visible from below (it is not the obvious but blind pothole) but can be reached by a 20m climb in two stages from near the base of the main waterfall. The climbs are easy if holds can be found in the moss and grass, however, for regular visits ladders are a sensible precaution.

Although a major resurgence cave, large streams can only be seen in short sections: from the entrance to sump 1 and just before sump 2. The entrance swim (avoided if visiting only the upper series by a traverse on the left hand wall) leads to a series of cascades carrying the stream from a rising sump. A dry passage leads to another sump pool and a rising crawl first explored by SIE, evidently with a pot of paint. The main part of the cave consists of a complex upper series of inlet passages and oxbows above the level of sump 1. These are reached by a climb up the left wall of the entrance rift about 20m in. Crossing over to the right wall half way up, a small chimney can be reached which is the easiest route. Unfortunately a nice body-sized hole leads vertically down to a stream below, so a ladder or rope is a useful precaution. From the top a short section of dry, but evidently flood-active stream bed leads past a major draughting inlet on the left to a large sloping chamber. This inlet is entered via a crawl into a moderately large chamber where large dog-tooth calcite can be found. A number of holes in the floor lead to a route to the roof of the lower streamway, but the main route is via a narrow rift. After a wet constricted crawl, a hading chamber is entered where the stream is briefly met, sinking into a narrow crack and rising from a tight sump. A small hole, not negotiated but surveyed through, leads to another route back to the main chamber. The inlet continues via a traverse around a drop to a pool (could be worth descending sometime) and along to two large avens and a final hading, very muddy rift which was climbed to a chamber. The draught disappears near the end, and it is quite likely that a way on exists here.

Three routes lead off from the large chamber. To the right a large passage with lots of muddy decaying stal floor ascends in steps to a large moderately decorated rift dipping at the standard 60° ish angle of the cave. At the far end a sandy crawl disappointingly narrows down, but a tiny (Ercina crayfish scale) mud-filled hole under the false floor draughts strongly. Back in the large sloping chamber the route to sump 2 is the obvious continuation. A large pool is passed; more evidence of impressive flooding. There is a reasonable amount of stal, in the form of flowstone, dry gours and the inevitable false floors, all of it dry or re-eroding.

Two oxbows are passed, the ascending one on the left leads up several climbs to a small steep inlet with a small stream. It climbs to the maximum height reached in the cave before it gets too tight. The other oxbow, on the right, consists of phreatic tubes and rifts in unusually dark limestone. The water-worn dog-tooth calcite (about 6" long) at one end presumably indicates development along a calcite vein. Stones were thrown about 10m down a narrow vertical rift in a pool - it was incredibly slippery, looked difficult and boring (i.e. we might find the bar shut if we bothered to descend it) and was therefore labelled 'another bit of sump 1' - although the survey now shows this to be uncertain.

Sump 2 is a large deep pool in the bottom of a large rift, the walls of which are covered in small sharp scallops. The sump is very convincing and a bit cool. The stream flows out of sump 2 down a short section of stooping passage, with amazing small, deep potholes in distinctly brown rock, to a frothy sump. The liberal spread of froth over much of the passage gives a pretty clear message! Sump 2 could probably be lowered with masses of bang but the most promising possibilities for extension involve climbing up the cross rifts. One of these above the near end of the sump pool was pushed by Skunk, it probably still goes but someone crazier than Skunk is needed. About 15m from this, back towards the entrance, another narrower rift was climbed for at least 20 m. Loneliness set in at this point and the rift was getting wider. With the nature of the cave high level passages would be expected.

Unfortunately for us nearly all the cave had been explored before and at least some of it surveyed. Both SIE and the SSSG left evidence of former visits. The latter left a nasty bit of cardboard with 'Explo et Topo 1977' scrawled on it, plus lots of cotton (apparently a French superman solo survey technique).

All in all a nice cave and with some potential for extension if you can summon any energy for caving after the somewhat strenuous nature of the walk to get to it.

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