Matienzo '93

For those who don't already know, I have over the last few years become heavily involved in a certain caving expedition to Northern Spain. I always feel that the expedition tag is not quite correct for these sojourns, as they are happening so regularly now. Matienzo is not unlike an extra (albeit distant) "British" caving area to myself and others. My first visit was in 1988 with six other trips since then. On this occasion I stayed for four weeks from late July to mid-August.

This summer more than sixty cavers participated in the 23rd British Speleological "Expedition" to the Matienzo area in Northern Spain. The limestone depression containing the village of Matienzo is located 25km south-east of Santander in the foothills of the Cantabrian mountains halfway between the Pyrenees and the Picos de Europa. The area of the depression is 26km2 and comprises of a number of valleys completely enclosed by hills of mainly Cretaceous limestone. The highest point on the ridge is at an altitude of over 800m (Mullir) with the valley bottom being at around 150m.

Since the initial visit of British cavers to the area in 1969 over 940 caves have so far been catalogued with over 160km of virgin cave passage mainly explored by the British Expedition. This summer 6km of new cave passage was entered and surveyed during a 6 week period from late July to mid-August, in addition to 13 new caves being discovered.

Vega Valley

258 - Toad in the Hole (Torcon de la Calleja Rebollo)

'Toad' is located on the opposite side of the Vega Valley to the South Vega System and it originally got its name on account of a certain hapless amphibian being rescued just before the break through in 1981. After several days of digging in a very draughty shakehole, a rather nasty entrance squeeze/rift dropped into a largish section of truncated fossil passage and 600m was initially surveyed. A further 1500m was then discovered in 1987 with another 2km in 1988. The trip to the end is now somewhat akin to doing a serious trip into Daren Cilau and is often consequently short of admirers. Placed between the great potential under Alisas towards the Ason gorge, and the increasingly likely-hood of a North Vega System containing Regaton, Mostajo plus other caves; it is in prime position to provide the key to that side of the valley. Unfortunately due to other more recent finds in Matienzo taking precedence, there are still many leads in Toad to be looked at. This year, several days were spent examining the North-East section of the cave nearest Regaton looking for a way on. Various draughting passages in an area called the 'Misty Series' were pushed and a number of small extensions found, ending in draughting digs that have yet to be pushed to a conclusion.

333 - Torca de Azpilicueta

On the opposite side of the Vega valley to 'Toad' several extensions to the South Vega System (La Sistema de la Vega) were made in both Renada and Azpilicueta bringing the total length of this multiple cave system to just under 22km. Small extensions were made in both the 'Sanatogen Passage' area of Renada and the 'Coffin levels' of Azpilicueta. This years biggest extension to the South Vega System came at the end of the expedition when an exposed bolted traverse around the top of 'Giga Hall' in Azpilicueta entered 300m of highly decorated passage. This has not yet been photographed which means unfortunately more suffering in 94' as the Azpilicueta walk in is arguably the worst in Matienzo and somewhat akin to a hot summer Tatham Wife Hole hike times five!


733 - Cueva Valline

Despite having dug into Cueva Valline in 1989, finding and surveying 9km in just a few weeks and leaving it with many leads still going, the expedition had been unable to re-enter it due to access problems until this year. Having renamed all of our passages and explored it as far as they could, this year the Spanish "invited" the British to come and help them push it. The bottom sump was dived by Phil Pappard to no conclusion and several other leads examined, including an aven and a strongly draughting boulder choke. Declining the offer of Spanish home made explosives we were eventually allowed to push the bottom of the cave without them for several days, attacking several leads that had defeated them. A bolt climb ended with no result but within two days digging, a major extension was found at stream level which is still going well. What access the expedition will be allowed to this new passage by the Spanish this summer is still a matter of some debate.

Four Valleys System

105 - Cueva de Riano

A very low streamway was entered via a small draughty entrance known locally as Dormouse Cave which is located only a few hundred yards from the main Riano entrance. An initial push eventually stopped, partly due to a flake that needed pummelling, and secondly the thought of an imminent neoprene smoke test asphyxiating the ferret (ie. me). The smoke test from within Riano proved a connection to Dormouse but the cave has yet to be joined to Riano. It is thought unlikely however to provide the hoped for easier route into the Four Valleys System.

107 - Cueva Uzeka

Two bolting projects were undertaken this year in Uzeka; the 'Astrodome' attempted by Tim Allen and Mark Wright, and 'Gour Inlet' by the Derbyshire Caving Club. The Astrodome is a 30m circular aven with a height estimated at over 100m. Averaging about 10m an hour, two days were spent bolting and despite problems on the way up they were eventually thwarted near the top at a height of 113m up when a chossy sand bed meant that the bolts wouldn't stay in. Looking up the last few metres through a hole at the top of the aven a small stream passage could be seen. The new plan of action is to bolt a scaffold pole into position 350ft up and then maypole into the passage from there, volunteers are now needed to do this ?!?!?

Chossy rock also frustrated the Derbyshire Caving Club trying to gain access to a large passage seen heading off at the top of 'Gour Inlet'. This time again only a few feet from the top and a maypole is suggested as a solution or possibly a different bolt route.


Each year several sorties of shaft bashing on the steep slopes of Muela (Mullir) are undertaken with only occasional successful results. Much of the work on Muela is aimed at trying to gain access to the ellusive theorised major horizontal development under this hill. This year we had partial success when two shafts, Torca del Triveno and Sima Levantada were connected and 220m of new passage discovered.

Fresnedo II

In 1991 a new cave, Fresnedo II was dug and explored through a tight choke to 1.4km of passage ending at a strongly draughting squeeze with a possible bypass called 'The Howling'. Last year the bypass pitch to the squeeze was entered, and extensions of over 4.5km were subsequently found making it the longest cave on the Fresnedo/Secadura ridge.

As last year there had been a number of tantalising glimpses of what appeared to be higher passages running above the main series, several trips this year were made to try and gain access to further extensions. Several new passages totalling 600m were entered off the side of the main route and one of these included a very large chamber with several new leads which may yet enter the hoped for higher level. The trip to the end of Fresnedo II covers most of its entire length and with the 10km round trip taking at least 12hrs to the present end, exploration at the far end of system is therefore very arduous.

A new entrance eliminating the marathon trip is now becoming a necessary objective to increase the productivity of Fresnedo II explorations and the search for the link to the caves in Secadura such as the Torcas de Simon & Cueva de Suviejo will continue.

Cubija Valley

The Cubija Valley is a small valley off the flank of the main Vega Valley to the Northern side. The most significant cave in this area until recently was Torca de Mostajo (71) with several other caves of shortish length being explored such as Simas del Picon, Torcon de Cubija plus one or two minor caves like Cubio de Cubija. Until recently most attention in the Vega area over the last decade has centred on extending the 22km South Vega System and finding the way on in 5km long Toad in the Hole.

Torca de Mostajo was originally entered in 1978 and a large fossil passage 300m in length stopped at one end in a choke and the other in a large impassable pit. In 1983 the pit was initially climbed and then more easily over-come by a long traverse, beyond this another 1km of mainly large and decorated passage was explored to yet another choke after a traverse. A 34m pitch to one side of the main passage was descended in the following year of 1984 and this dropped into the section called 'The Golden Void' which has a 4.5km complex of passages leading away from it.

At Easter 1992 a strongly draughting entrance shaft was found further up the Cubija Valley in a small copse and this was pushed down four ladder pitches to the top of a large aven and finally a big loose pitchhead. During the subsequent summer the 60m pitch was finally descended on SRT and at 100m depth a small stream passage led off west.

Following the stream for a few hundred metres to a sandy junction a large 20m wide trunk route named the 'Power House' was followed North that eventually ended after over 1km at a large draughting boulder choke. A few days later whilst exploring side passages a short distance in, an inlet was entered that gave access to another large phreatic passage called 'Skye Passage' heading West. This was pushed until after a few hundred metres a large chamber was reached with two ways off. Being right at the end of the 1992 expedition, and having only one trip to have a look before the cave had to be de-tackled, the larger of the two passages was surveyed for a stomping 500m until a draughting boulder choke eventually stopped progress.

The first trip down Torca de Regaton (892) this year initially looked at the second of the passages leading off from the junction at the large chamber. The smaller passage initially ran South as a low cobbly crawl but soon went easterly and headed upstream as a small water worn passage. For over 600m the passage continued - mostly walking size - past several avens as well as cutting through phreatic tubes en route. After a low section and a duck, eventually a climb stopped progress. Just downstream of the climb a large sandy and bouldery ramp was ascended leading to several hundred meters of passage, some of which has still to be pushed to a conclusion. The 10m climb at the end of the upstream passage was scaled to a continuation and eventually ended at a draughting choke.

Much in evidence at this end of the cave was flood debris of varying make-up particularly characteristic of Matienzo. This included the usual twigs, leaves, bits of blue plastic buckets, a child's plastic yellow horse, Domestos bottles, containers of unknown smelly substances, and the obligatory dead dog. As somebody pointed out, "we must be near to the surface because a dead dog wouldn't be able to go very far by itself". The computer survey and the nature of the flood debris indicated that there must be a back door into Regaton somewhere nearby on the surface. Having shown the local farmer the plastic toy and asked him if he knew the "source of the horse" and received understandable blank looks we started to poke about on the surface.

According to Juan's computer system a cave/sink called Cubio de Cubija (243) was located almost on top of the upstream section in Regaton that we had just discovered. In true Matienzo style we firstly examined the local farmhouse refuse tip closely and drawing a blank, Cubio was then checked as it was only a civilised 10yds from the cars; a perfect entrance! We knew almost immediately that Cubio was probably what we were looking for as the vegetation surrounding the entrance was waving wildly about in the wind roaring out of the entrance! Cubio had a recorded length of only 100m, so why did it appear to finish and emit such a strong draught? Several hours were then spent extensively searching for where the draught was coming from and most of it appeared to be coming from impenetrable cracks in the floors of two chambers reached by short ladder climbs. At the base of one of the drops described as "a chamber with no exit", a tight squeeze was eventually pushed and led to a maze of small rifts not previously entered before.

Following the rifts past much flood debris and a 5 inch long Salamander, a short climb eventually forced a retreat. Returning the following day and surveying in, the 10ft drop was descended and a very low, wet and tight water filled passage was followed to the top of a drop into a largish chamber. This route would have been too small to allow most normal sized people through; so another route was eventually found via a low wet canal to the top of a small aven that landed next to the pitch before the final drop into the chamber. By precariously tying ourselves to the last ladder, myself and Phil Miles could lean over the edge and see a survey cairn at the base of the pitch in a chamber recognised as the one that had been found at the very upstream section of Regaton. However not having enough ladders left to descend the final pitch into the chamber a tantalising return to the car had to be made before the final 25ft connection descent could be made.

The Cubio entrance greatly facilitates exploration into Regaton as the danger of falling rocks and the people jam due to having to prussik up the big pitch at the old entrance is completely eliminated. All trips for the rest of the expedition were via this new entrance despite one old timers view that Cubio's a "sharp, grotty, miserable cave that we wouldn't have bothered with in the '70s".

The most Westerly passage that had ended at a choke the previous summer was now looked at again. Below the terminal choke a small passage was pushed that seemed to be the outlet for floods in that part of the system but ended too tight after 100m. However a way through the choke was found via a rather nasty section of jammed blocks and the cave "went" again. Beyond the choke a continuation of the walking sized passage led almost immediately to a very large chamber with only one apparent way off. For 300m a large - but awkward to negotiate - passage over blocks was followed to a another large chamber full of break-down and holes in the roof. After descending a short climb a further 150m of passage was then followed to a 90ft draughty muddy pitch to a lower active streamway that is about the same level as the flood outlet seen back under the 93' break-through choke. Two ways off were then discovered at the bottom from here totalling over 200m of passage with one sumping but the second containing a draughting boulder choke heading West still to be pushed. This streamway is so low such that it probably resurges not in Matienzo valley but Cobadal.

Back from the top of the 90ft muddy pitch a small rift out of a muddy, bouldery chamber led surprisingly to yet another large passage heading off. This was followed for over 300m in great style until eventually a small streamway was eventually met. (Within this section an extremely thin frog was found alive and quite how it got to be so far into the cave is another mystery that might be solved in 1994). Upstream was very low and wet and ended at large muddy chamber, but down stream continued until it suddenly ended at a very draughty deep pool with low airspace. On a return visit with wetsuits 500m was surveyed with most of the passage being either out of depth or very wet but quite negotiable in size. Several side passages were initially looked at with the main passage ending at a draughty boulder choke, the whole passage appears to flood dramatically due to the large amounts of flood debris being present.

Due to the closeness of other known "old" caves in the Cubija Valley and our success with extending Cubio and Regaton it was decided that a return visit should be paid to some others.

75 - Simas del Picon

Simas del Picon was a 600m long cave that has been known since the 1970's and was originally explored by the Spanish. The cave is basically one extremely large tunnel that divides into two "smaller" passages both ending at chokes. Initially this summer a new survey of Picon was firstly taken by the Plymouth Caving Group and after processing on the computer several interesting facts came to light. Although Picon was significantly higher than Regaton it ran right over the top of it and its main passage level was at the same altitude as that in Mostajo nearby suggesting a possible common relationship.

On a so called day off when the rest of the expedition were on a tourist jolly down Ojo Guarena (Spains longest cave); myself and Ian Walton went into Picon to have a "quick" look. The left hand branch ended at a pit that we didn't descend and the right hand branch appeared to end at a stal choke. However upon close scrutiny of the calcite slope an odd cold sensation was noticed on the extreme left hand side and a draught appeared to be emerging through some long stal that didn't look too indestructible. Not having a lump hammer to hand, I used a fist sized rock to good effect and a route was knocked through the grotto in only a few minutes. Through this scene of speleothem devastation and increasing draught I squeezed until I had engineered a route of minimum vandalism that dropped me down the far side of the blockage. Not quite believing what we were seeing the two of us then walked 200m down a beautifully decorated walking sized passage containing masses of stal and helactites (see front/back cover of Caves and Caving No.63/Spring'94). Eventually a very steeply descending sand ramp barred any further easy progress and we made our exit sniggering like two smug naughty children all the way out to tell the others.

On subsequent trips the ramp was descended to the top of a 20m pitch which dropped into 200m of passage thru' draughting digs to several small chambers quite close to Regaton in both plan and elevation. Another climb near the top of this sandy ramp plus several other leads still to be pushed may yet link to Regaton. A bold traverse around the top of the 20m pitch head, sees the continuation of the large phreatic passage but this closes down after 150m at a draughting boulder choke. This section also contains spectacular formations on route.

67 - Torcon de Cubija

Torcon de Cubija was the next cave to receive attention in our search for links to Regaton and Mostajo. Torcon, like Picon had been explored by the Spanish and had been looked at by Matienzo expeditions in the distant past. Once the cave had been resurveyed for the computer and plotted in relation to Mostajo, it could be seen that it was just 30m in plan and 20m in elevation away from Mostajo. An initial visit to Torcon has shown the possibility of extensions and the very real chance of connecting it to Mostajo on following expeditions.


A visit to a Camargo cave, Caliente-Frio, near Santander was organised by invitation of the Grupo de Espeleologia Investigaciones de Carbollo/Rada and some surveying and pushing was undertaken. As usual this was arranged by our ex-pat. Pete "Pedro" Smith and our good friend Carlos of Santander. The day went very well until we "broke" our Spaniard (Carlos) when he fell off a short climb! (I saw Carlos this Easter and his arm has thankfully mended.)

Another scientific project was initiated this year and a number of large, dirty stal were removed from Cubio-Regaton, Fresnedo, Azpilicueta and Cueva de Agua. Steve Oppenshaw is carrying out a magnetic study of each, using a SQUID magnetometer to obtain secular variation data, and dating using Uranium-Thorium dating techniques. The results should allow the construction of a composite secular variation master curve for the area. Data obtained from this work on stalagmites from Matienzo and also Xingwen in China will be used by Dr. Dave Gubbins at the University of Leeds as part of the Earth Field Modelling Project.

Matienzo is an "open" long-term Expedition organised by a loose collection of cavers from various clubs who have visited the area for a number of years. New faces to the expedition are always welcome and cavers of varying experience will always find something to contribute to the speleological work given a little guidance. There is much work to do in and around the depression but the discoveries only proceed at a satisfactory pace when all visiting cavers integrate into 'Matienzo Caving Club' and commit themselves to the area or a system over a number of years. (Cavers who 'milk' the area and don't put anything back into the expedition survey drawing and writing program are NOT encouraged.) If you are interested in trying the 'Matienzo experience' and wish for more information then contact me via the usual channels and I'll see if I can help.

And finally thanks to...

Juan Corrin for providing the area map and much of the inspiration and enthusiasm to keep the expedition running smoothly.

The villagers and the authorities who allow us access to cave and offer us hospitality during our annual visit to Matienzo.

Ghar Parau Fund committee and NCA for the Sports Council Grant.

MATIENZO '93 - Lengths Surveyed

Cave Surveyed 1993 (m) Cave Length (m)
Cubio - Regaton 3805 7089
Picon 682 1241
Fresnedo II 644 6761
South Vega System 431 21906
Hoyo Verde 177 177
Jane's Cave 143 143
715 135 135
Gato Montes 86 86
415 79 908
718 72 72
Torca del Triveno 61 220
Toad in the Hole 42 4999
Tras la Cotera 38 38
Total 6395 -

By invitation in Carmargo, Santander

Caliente - Frio approx 500 -

Principal Rivers and Caves of Matienzo Area

Principal Rivers and Caves of Matienzo Area

Paul Stacey