Updated 15th, 22nd October, 2nd, 14th, 24th November, 7th December 2014; 7th October 2015; 19th February 2016; 1st July 2018; 24th May 2021
This is one entry point into the Riocueva-Cañaos system. There were at least 4 entrances and these are included in the table below. A new detailed survey was "completed" when the cave was surveyed through to Cueva Riocueva, site 4042 in October 2014 then pushed upstream in August 2015. There are still (October 2015) a couple of leads to push and survey.
| code | name | altitude (m) | notes |
|---|---|---|---|
| 4043 | Torca de los Cañaos | The 14m deep shaft entrance where a number of passages lead off. The "top entrance". | |
| 4084 | shaft (capped) | This has only been seen from inside Riocueva-Cañaos where concrete and surface debris litters the floor of an aven which presumably reached the surface before it was capped. | |
| 4042 | Cueva Riocueva | The green-gated entrance to archaeological excavations and the rest of the system. The "middle entrance". | |
| 4085 | cave | The "bottom entrance" into the Riocueva-Cañaos network close to the flood resurgence. | |
| 4086 | cave | Hole just above the flood resurgence. | |
| 4087 | resurgence | Flood resurgence. | |
| 4088 | resurgence | A number of places below the cave where water resurges in dry weather. (Not enterable) |
Torca de los Cañaos is in a large, vegetated depression with a small trickle (in dry weather) collecting and falling into the impressive entrance shaft. The grid reference and altitude (to the bolts at the top of the pitch) is the result of surface surveying (batch 14-19). An estimate after a GPS reading outside the depression was 30T 0443546 4805707.
The cave has been explored to a large extent and documented by Spanish cavers. Published articles about exploration can be found in at least Cuadernos V - VI and Cantabria Subterránea vol. 1 (pp 274 - 277; 61Mb download) and these articles need putting in the bibliography and below. The surveys from these articles are found below, although they are incomplete. The Cantabria Subterránea article hints at a number of passages not surveyed at the time of the earlier explorations.
Archaeological work has been carried out in the Cueva Riocueva entrance passage, observed in 2014 and that cave is gated. Again, more details will appear from archaeological references. A blog for the Mauranus Project has a number of details, including pictures from 26/10/2014 when the Matienzo Caves team entered through the Riocueva entrance to survey the links through to Torca de los Cañaos.
As entry to the system cannot normally be gained through Cueva Riocueva, all Matienzo Caves Project exploration in the system is documented on this Cañaos page.
The Cantabria Subterránea article mentions two rescues that have occurred in the system. In 1983, a fall down a pot in the Galería Mabe resulted in various fractures. In 1988, a caver fell at the Paso del Diablo, in Galería Mabe, suffering bruising and a cracked rib.
Entrance shaft
This is documented as 18m deep but, when laddered through a narrow notch on the shaft lip, just to the right of the water trickle, it was measured at 14m deep with the ladders tied back to the largest convenient tree. Subsequent pitch descents have been made using SRT from bolts at the left hand wall, tied back to a tree, with a couple of deviations taking the rope out of the descending crack. The vertical drop for this pitch is also 14m.
The base of the shaft is covered with boulders, bones and rubbish, including tyres, in a large chamber. A number of passages radiate from here, one down into the streamway and others to high level routes.
A measurement of the radon concentration around July 24th 2014 gave a reading of 460 Bq m-3
Galería de Yeso and Upstream
The Galería de Yeso was the first gallery looked at in May 2014 when exploration by Matienzo Caves Project members started. From the entrance chamber, the obvious bouldery route downhill to the northeast goes past a small window down on the right to the stream (guarded by a tyre) and then levels out into a generally walking passage, which becomes more decorated with dull gypsum crystals. This fossil passage, with good decorations (and photo opportunities) in places, also has excellent hanging floors where stream cobbles are exposed under other calcited sediments. The route continues for more than 760m, over boulders with drops down to the river and holes at roof level then through a couple of lower contortions near the end, to an excavated hole through into a small enlargement with routes right and left that are too small (batch 14-00). There was no apparent draught in warm weather at this point and the passage is approaching the surface. The Spanish survey ends a few stations back from here.
At a number of places through this gallery there is evidence of previous explorations: carbide dumps, black carbide graffiti on the walls, broken stal and litter, etc. The Matienzo Caves survey of the gallery (batch 14-01; length 767m) is a centre line with some station markers but with no attempt to explore and survey side passages on that first trip. Subsequent visits in the summer and autumn pushed many of the leads off the Galería de Yeso and these are described sequentially from the entrance chamber in the following expanded description.
Yeso Oxbow (batch 14-11; length 21m) At the first crouching section of the Galería de Yeso a short oxbow rises on the right, noteable for a large gypsum "chandelier". The passage swings to the left along a hading rift before rejoining the main route at a small climb down.
A short climb over stal then reaches about 110m of walking in 5m wide, mud-floored passage to a pile of boulders. A few steps over the top of these gains the continuation of the Galería de Yeso, but routes down between boulders to the east and west drop to the streamway.
Downstream segment (batch 14-12; length 126m) A crouch to the west through the boulder pile drops down to a walking / stooping size passage which, in common with much of the streamway, has low banks of cobbles. About 60m downstream a high aven on the south side connects to Galería Mabe, 7m above. After a further 65m, the water becomes waist-deep and the passage has not been explored beyond this point.
Upstream segment (batches 14-13, 14-16, 14-28; length 501m) As well as meeting the upstream continuation down a slope of boulders on the left (north) side of the Galería de Yeso, this 500m length of streamway can be entered down a slope and tight crawl further along the Galería de Yeso, after the rock ribs, at station 14-01.51. A crawl over cobbles is met about 50m upstream and then the water deepens, with mud banks, until the passage develops along a tall rift. Straight ahead, starting with deep mud, a squeeze through and steep crawl up meets the Galería de Yeso. To the left, a deep canal and duck emerges in more cobbley stream passage with a 31m high aven on the south side. The passage continues upstream for over 100m to a duck which had leeches in 2014. Small pockets of formations are passed, including "black mini gours", until the passage narrows and the water deepens, necessitating a swim. The passage has been pushed a short distance further upstream to a duck/sump chamber, probably about 40m from the "low duck" which currently ends exploration in the final streamway segment - see below.
Back at the boulder pile, the roomy, sediment-floored passage continues, immediately encountering walls of carbide names and a hole in the roof which is a 3m roped pitch down from the Galería Mabe. About 70m further on, stepping over rock ribs leads to 2 ways on - high and low level crouches - which quickly unite at station 14-01.51 and the route down to the stream. The way on enlarges in a 6m high and damp chamber and, where the floor level route constricts at a "portal", a short climb on the right enters 25m of unsurveyed tube. Continuing south, the cave passage becomes better decorated with the Another Anorexic Porn Star column and various stal pendants and floors.
The route narrows slightly then widens just past some obviously "planted" stal, with more formations and some unexplored possibilities on the east side. About 25m beyond the last of these - an unexplored 5m drop - a large block marks the survey station and short climb up into the northern entrance of the Western Loop, described below. The route enlarges, with the bigger oxbow passage up to the left (batch 14-34) and the usual, smaller route straight ahead. After a few metres the passage becomes smaller ahead (an oxbow, batch 14-10) and the main route turns left to meet up with the oxbow at station 14-01.31. The main route continues past more side routes and various small possibilities until the passage enlarges at a large column. Here, a climb up an inclined rift heads back to a choke and, at the low level, stream cobbles at head height protrude from below a calcite cover. There are a number of possibilities for extension in this area, including "digs down with water below" (batch 14-07).
The passage becomes small and a couple of short crawls through stal unite to meet one of three entry points into Bold Step Passage on the right. A few metres further on, where the passage swings right, another tiny entrance is seen on the right, just before a hands-and-knees crawl over muddy gours and a short climb up at a pendant stal. Thirty metres further on, another focal point in the cave is reached, Bold Step Chamber, just beyond a 3-piece stal arrow on the floor (station 14-01.11). At floor level a short passage to the west ends at a large broken stal and a ledge and aven above.
Love Heart Passage (batch 14-05, length 37m) A bouldery entry point off Bold Step Chamber passes into a rising, narrower passage to the east and south. The passage then descends under an aven and ends at a mud choke.
Western Loop (batches 14-08, 14-09 and 14-14, length 326m) This is entered up a short climb to the west. Back to the northeast is Bold Step Passage, described below; to the west is a short passage ending at a veranda with a view down to the broken stal, while to the southwest, a narrow, 2m-high passage meanders for 25m until a short climb up intersects the main, Western Loop, passage. To the south, the 5m wide passage is nicely decorated but becomes increasingly muddy past tree roots and holes in the floor. The end has not been pushed and there are possibilities between stal.
To the north, the route starts low but enlarges at formations. To the left, high level holes have been investigated and choke. Cobbles and an uncertain left hand wall are past and further cobble deposits are seen as the passage passes over the Galería de Yeso. The passage lowers to a decorated low crawl just after the passage splits. The route passes through a grotto and swings right past "SESS" in carbide on the left hand wall. The passage then widens and becomes wetter at a chamber. To the left a crawl on mud passes a yellow jacket and ends at a sculptured skull where there is a stal blockage. Straight on, over a 1m high mud bank and past some mud sculptures, the small route ends at a short climb down into the Galería de Yeso at station 14-08.24.
Bold Step Passage (batches 14-35 and 14-36, length 91m) A bold step over a 2m drop enters a passage that rises up a slope to the west to an aven with a possible passage. To the north, the well decorated passage becomes smaller as it passes back and forth over the Galería de Yeso and eventually links with it in two places near the muddy gours crawl.
Beyond Bold Step Chamber, a low, excavated passage on the left (west) side leads through a flat out crawl to a narrow climb down into the stream. The streamway is described below. The main route continues past muddy stal in a wide bedding. A small chamber is soon reached beyond a hole in the floor. Ahead, through a low squeeze, all routes close in. To the west, over the hole, a small, crawling-size passage has "Stop" in carbide on the wall near the end (batch 14-03). Beyond, an excavated section ends where it is possibe to look through into an enlargement - probably the southern section of the Western Loop.
Southern-most stream segment (batches 14-26 and 14-04, length 206m; batches 15-03 - 15-06 length 281m) Down the hole in the floor, the stream is met again. Upstream has been pushed past an oxbow and duck to a short climb into high level passages. These end at an 8m pitch to a pool after a number of side passages which have digging possibilities. Back in the stream, the low upstream route becomes extremely unpleasant through low ducks in runny cow shit with cow shit snottites. The streamway currently ends at a dig in silt. (This needs a better description? No batch description for 15-03 - 15-06.)
Downstream passes a low section to meet the route in from the flatout crawl and climb down. The cobbley streamway continues to station 14-26.10 where a 2m climb on the right enters a draughting bedding plane which is unexplored beyond a stal grille. After more than 100m, exploration downstream has stopped at a sandy chamber with a low duck which has not been passed. The water is presumed to flow to the duck/sump chamber about 40m to the north.
Galería Mabe, Galería Emeuve and beyond (batches 14-15, 14-17, 14-27, 14-29 and 14-30, length 788m)
The obvious hole 3m up on the southeast wall is the usual entry point to this set of high level passages. There are three connections between the passages.
Galería Mabe At the top of the 3m climb a calcite-floored chamber is entered and at the far side a passage runs south then east for about 100m to the Paso del Diablo. On the south side of the gallery there are passages sloping up into the Galería Emeuve series, described below. The Paso del Diablo is a roped(?) traverse over a 4m deep pit to a continuing passage. Fifty metres beyond, a route to the left ends at a 3m roped pitch into the Galería de Yeso near the boulder pile and stream connection. Passages to the south of this connection have no passage or description detail, although there could be a flatout crawl involved (batch 14-29). A parallel route to the east has an unexplored 5m deep rift (batch 14-30). Description of these 2 batches required.
Galería Emeuve This series on the southern side of Galería Mabe was not on the original survey but was briefly described in the article in Cuadernos V-VI. It consists of a series of passages and chambers which connect with Galería Mabe in several places. It can first be reached up a short scramble on the right hand side of the Galería Mabe, about 70m from the Cañaos shaft. A low passage immediately leads into Volcano Chamber, the cave’s largest volume, about 20m long and 12m wide. According to the survey, this is directly beneath the road, which is about 20m above the roof of the chamber. Two passages on the west side of the chamber connect at the start of another large chamber with some fine formations. A hole on the right drops back into Galería Mabe, while a crawl at the end of the chamber reaches a final room, adorned with a mysterious old glove on top of a stalagmite. This is extremely close to a passage reached on the other side of the Cañaos shaft.
In Volcano Chamber again, a mud slope on the eastern side leads up to a passage that breaks out into a wider area and slopes down to the top of a shaft. The return to Volcano Chamber can be made along a crawl which connects with the mud slope.
The second part of Galería Emeuve is reached at the top of a second steeper climb up the right-hand wall of Galería Mabe, some 20m from the first scramble. A crawl soon comes to a pit in the floor (which is still undescended). The aven above this pit is in fact the shaft seen earlier off Volcano Chamber. The pit can be traversed on the left hand side and a passage on two levels soon comes to an aven. The rubbish at the base of this aven, much of it calcited, shows that it is the shaft that was open to the surface in the 1960s but which has since been capped. (The surface position is documented as site 4084). There is a short low passage at floor level, but the main passage continues for about 25m to a sharp right-hand turn. On the corner a narrow slot apparently drops into Galería Mabe on the far side of Paso del Diablo. Now heading south-west, the passage becomes narrower and chokes after about 30m.
Routes towards Cueva Riocueva All of these passages are entered up a short climb at the southwest side of the Torca de los Cañaos entrance shaft. Six metres later a short climb down reaches a chamber. To the left (east), a low passage links back to the shaft though rubbish and boulders. Climbing up to the right from the short climb reaches a slot back down through a clean-washed area and climbs down to the stream. To the right of the slot is an undescended passage. Part way up the climb to the slot, going off left over boulders leads to higher level passages. Left leads to stal chambers close to the Galería Emeuve series. Right, after 25m keeping up left here gives access to the Galería del Laboratorio series while going down to the right accesses Galería del Tembleque, in which pitches down are alternate routes to the stream passage and also Stop Passage.
Streamway segment downstream to the surface (batches 15-01, 14-24, 15-02 and 14-25, length 439m) From bottom of the entrance shaft the lower west passage leads to breakdown with a link to the upper passage. A slot down on right leads to a decending rift to meet the 4m wide 2.5m high river passage some 40m from the choke under the entrance (lots of bones and surface rubbish but no obvious way through). Down stream the passage roof opens up to a rift that connects to the upper west passage.
The streamway (River of Bones) starts littered with animal bones. After a hundred or so metres of downstream progress, the stream disappears under the right hand wall in a series of small rifts (shown on the Spanish survey). The continuing overflow passage passes boulders and has standing water. A decorated crawl over mud widens to a possible hole up to Stop Passage and the Paso de la Muerte. Downstream continues through a chamber where a slope up on the right links via a 3m climb up to the Cueva Riocueva entrance passage. (However, this possible free climb may to be tackled up from above and, even if found with a rope or ladder, the Riocueva entrance is likely to be locked.) The fine streamway continues for another hundred metres to where the water sinks away on the right and a flat-out crawl shows approaching daylight and the stooping walk-out at the bottom entrance.
Just downstream of the big oxbow on the north side of the streamway (50m west of the entrance shaft) is a bold step into another but narrower oxbow (part batch15-02). This starts level over a mud floor to a decending passage 0.6m by 1m high over old gours to meet the river overflow passage some 50m downstream of where the river in dry conditions outlets. Just back upstream of here, the stream enters a narrow rift passage which is shown further explored on the Spanish survey.
The Galería del Laboratorio series including the high level extension (batches 14-18 (part), 14-21 and 14-32, length 312m) The left hand route at the 3-way junction enters a mud-floored passage that soon passes under a 5m pitch up (described below). The main route continues for about 80m to a stal choke, passing through several excavated sections.
The climb up at the p5 (batch 14-21) is easy if aided by passing a ladder/rope over a large flake at the top and it enters a low passage leading to a small chamber, at the top of which pretty passages run left and right. That to the left leads to the squeeze through stal which has been enlarged. This was later surveyed as batch 14-32 to end choked with more stal. A p5 was descended and surveyed as batch 15-07: A muddy slot drops into a small, bouldery chamber. Right, facing the pitch, is blind and left leads via a small crawl into an smaller aven chamber. The aven is 10m high and was climbed for 7m until it becaome too difficult. There does not appear to be a way on at the top, but that is not certain. (Alex Ritchie)
Galería del Tembleque (batches 14-18 (part), 14-33 and 4042-14-04, length 278m) The right hand route to the south at the 3-way junction enters a mud-floored passage, through a stal grille and past a high level oxbow where there is a possible traverse to a passage. The passage encounters rifts down to water which may show up an inaccuracy on the survey. Just beyond, at station 14-18.44, a climb up on the west wall reaches a decorated gallery that soon closes in after splitting (batch 14-33). A roped traverse (length?), the Paso de la Muerte, safeguards the route past various drops and the p8 down to Stop Passage (see below). The gallery continues to a squeeze between stal and, about 90m further on, a 4m drop. Below is the main archaeological passage in Cueva Riocueva and it is possible to climb carefully across and traverse down to the floor. At high level, Galería del Tembleque continues through a crawl and past ochre deposits on the north wall to an area of false floors. Beyond, past 2 pits, the passage becomes smaller with continuing crawls over bat and fox guano as it approaches the surface.
Stop Passage (batch 14-31, length 97m) To the east of the Paso de la Muerte, an 8m pitch drops into a decorated chamber with a route down to the stream. Stop Passage leads out to the west and is a bouldery and well decorated passage to a choke - finishing very close to the choke that almost closes off the end of the archaeological passage in Cueva Riocueva.
Cueva Riocueva (batches 4042-14-02 and 4042-14-03, length 267m) As described above, there are two ways into the archaeological passage from Torca de los Cañaos - up from the stream or down from the Galería del Tembleque. The latter route is more likely. At the base of the climb down into the archaeological passage, a short distance to the northeast ends in a choke. The only way through is a low section to the right that rises then passes through a squeeze to the top of a short drop into the streamway. The drop is bolted at the top and a ladder is best although a rope has been used. (It is a free climb if you know where the concealed foothold is partway down.) Just before the drop, a short climb up to the left enters a bouldery, choked chamber.
To the southwest from the Tembleque climb, the roomy passage passes a large stalagmite to reach a slight enlargement with a bouldery floor. A passage a couple of metres up the left hand (south) wall continues small to end after about 60 metres where the passage splits into three. The centre route is diggable and is only a few metres from the Riocueva entrance chamber. Continuing in the main passage, a number of archaeological excavations can be carefully stepped over. A short crawl then enters the entrance chamber which is normally gated at the exit. (Photos and video of the passages near the Riocueva entrance are found in the Riocueva description. The 1983 video on YouTube shows the Riocueva passage and the route down to the stream, then the return.)
Site description by Juan Corrin, Alasdair Neill and Peter Smith, and from log book accounts.