Updated 5th March 2000; 14th May , 17th September 2000; 23rd February, 26th April 2001; 12th November 2002; 15th October, 8th November 2003; 14th May 2004; 1st February 2006; 6th January, 2nd October 2011; 18th February 2012; 23rd April, 20th September, 28th November 2012; 21st, 29th April, 13th, 16th September, 21st November 2013; 16th May 2015; 30th June 2018; 11th May, 6th September 2019
[Description improved and tidied up by Alasdair Neill, November 2013]
There are two entrances each being a pitch (35-40m, and 15m). The lower 15m pitch is perhaps best laddered, but is also rigged for SRT with a spit rebelay partway down, and an optional deviation can be rigged from an overhanging tree branch. The higher pitch may never have been descended; where it enters the roof of the main passage a rift can be seen to lead to a possible passage or aven. Both entrance pitches land in a most impressive passage, some 20 to 30m wide.
Heading east (back towards the surface) from the bottom of the usual entrance pitch, there are a series of bouldery crawls which choke with no discernable draught found.
The main passage from the foot of the entrance pitch begins as a slope down over mud and boulders with assorted debris including various parts of electricity pylons.
Large passage 50m from entrance.
After 50m a large passage slopes down to the left, much of it being flowstone floored. Several small passages lead off on the left hand wall. The passage continues large and sloping down, as far as a wall which was climbed and bolted up on the left hand side at Easter 2013. Twenty five metres up, the climb ends at large blocks but no way through can be found. The rope has been removed and one bolt remains at the top.
To the right of the foot of the climb, the flowstone floor leads to a draughting flat out bedding. This immediately opens out into a chamber, where in the summer of 2013 vocal and molephone contact was made with the Megabat Series. A drop through boulders on the left hand wall, under a loose rubble slope, leads to a passage taking a stream in wet weather. This ends at a diggable choked slot. A chamber to the left enters a draughting choke. This area has since been dug by P. Smith & Nigel Dibben (description?). The loose rubble slope can be climbed up through a very unstable area to connect to the floor of Sala G.E.S., this route is not recommended and Sala G.E.S. is more easily reached on the main route.
Main way on (continued)
The main route further into the cave is found by staying up to the right rather than following the large passage down to the left, 50m from the entrance.
Picón Eye Series and other side passages
Almost immediately, a broad ledge to the left, over the top of the large passage, leads to where an eyehole in the far wall is the start of Picón Eye Series. A wider passge to the right leads to a chamber, where tree branches below an aven perhaps indicate another entrance. The Picón Eye Series was entered at Easter 2013, through the eyehole. A short pitch down enters a passage to a choke after approximately 7m (5m wide sloping up). Over the top of the pitch, three traverses (23m rope) to the left lead to a chamber (which had a bootprint !) and a very impressive column. (Below the traverse, the drop connects to known passage). Three passages go off from the chamber: two are short and the third goes to an aven and a 10m pitch.
The p10 was descended at Easter 2015: 1.5m up from the base, a tight crawl continues for about 6m in 1m high, meandering passage. There is a weak draught and echo. At least 3 snappers are needed to progress. Above the p10 is a c+5 which enters a meandering passage. This ends about 7m up the aven seen a short distance further on. Bolting up this aven will be easier from this meander route. A video shows some of these Easter 2015 activities and the 2013 survey has been amended.
Main way on (continued)
The main way on is to the right of the start of the broad ledge leading to Picón Eye Series, and after a short climb up enters Sala G.E.S. In this chamber, rifts on the right hand wall were climbed in 2001 and again in 2013, but are blind. After Sala G.E.S. the route is down a slot on the right hand wall. Beyond the passage gets much higher again and slopes down. Here traversing off along the slope to the left is the way to Mega Bat. There are also some high rifts up, possibly not fully explored, on the left where Mega Bat goes off.
This starts as several small holes leading to a small chamber. Going right then left through a short excavated crawl, the route breaks out into a decorated chamber. Beyond this a short continuing passage leads to pitches of 9m (bolts in roof) and 7m (bolts to the right). This originally ended at a strongly draughting slot with a chamber or pitch beyond - then described as very committing but possible for a midget. This slot was investigated in the summer, 2011, when the newly-discovered Patrick's Error in Cueva de la Morenuca was surveyed. The extension appears to pass under Picón with the floor about 30 - 40m below. At Easter 2012, the draughting slot was enlarged and further enlargement in the summer finally succeeded in opening up the way on. The squeeze was finally eliminated in November 2012.
The descent (originally described as a 5m muddy handline climb down reaching a 60 degree slope) is best tackled with a 30m rope. A small, sandy crawl traverse goes into the slope. Passing over a ridge (0.5 x 4m) with a 2m drop on each side leads to a 3m diameter chamber. A crawl to the right goes for 5m to a window into the ceiling of a chamber, about 5m tall. The description ends with "there are 4 chambers, one of which with a 60m aven, the rest have no obvious leads. Halfway down the handline pitch there is a draughting rift leading to a large chamber. Abseiling into the draughting rift needs care. Boulders fell on one person in 2012, requiring 4 stitches in the head. A short crawl on one side of the chamber leads to a 40m tall, 8m diameter aven. Another crawl would be possible with a hammer. On the floor of the first chamber, a squeeze goes to a 6m diameter chamber with no way on. Climbing up at the rear leads to a small chamber. A 4m fairly shear but climbable wall goes to a window at the top that has a weak draught.
These passages and chambers at the base of the slope are apparently at the same altitude as Picón Pie Chamber and must be extremely close. It will be worthwhile having people in both caves to prove the connection and possibly forge an easier way into this part of Morenuca.
In the summer 2013, a major extension from Safe Haven was entered. A small squeeze leads to a boulder choke and a route through to a 10 x 10m chamber with a large passage coming off. (Batch 13-12). This was eventually pushed (batch 13-13 and batch 13-14) to very close to the bottom of the slope down from the entrance pitch. A dig at the base of the slope was excavated for 6 hours but the "vocal connection needs to be checked".
Main way on (continued)
To the right of the slope down which leads to the start of Mega Bat, the way is to climb a high, steep rubble slope, the Scree Run. This is the start of Sala de los Bloques. This is a large chamber which in part forms a large junction; the high left hand passage ends at an 8m deep shaft, the continuation beyond this being the A.S.C. Extension.
The 8m shaft forms the floor of a rift passage some 20m high. In April 1994, the Association Spéléologique Charentaise climbed up some 15m around the side of the pit to reach what was described as a 40m diameter aven and a calcite slope which closed in after 50m.
The ASC Extension was rebolted, re-explored and extended in the autumn, 2012. A 16m bolt climb on the left hand wall above a pit leads to a hole at the top and a pitch down.
However, in 2012 the ASC bolt climb and pitch down was bypassed. A traverse around the 8m shaft on the right hand wall and climb up reaches a small excavated drop which bypasses the up and down pitches. This traverse is still rigged (summer 2013).
The down pitch lands at the base of a 31m aven with "lots of bat shit about". At the western end is another short pitch to the base of an awkward slope / climb to a draughting dig up in boulders. This has been excavated into the Melted Wax Candle of Doom Chamber with a diameter of 12m and some roof and floor formations.
The eastern end has a scramble / climb down to the base of a climb - now a rigged handline up to a rigged traverse line around the original pit.
The Melted Wax Candle of Doom Chamber has some possibilities for extension. In the southeast corner, a climb down into a crawl in boulders although this area is loose and the "wall in the chamber is badly attached." In the western corner it is possible to climb down under boulders. A few bolts may be needed to check a possible passage in the roof. To the north, a 20cm rift was opened up at Easter 2013 to access a 4m deep rift. This led to a well decorated grotto, 4m in diameter with a pool. A crawl leads off to a 3m diameter chamber with boulder walls and no way on.
A potential bolt climb up the wall above the last pitch down was originally described as appearing to be up into a large passage - the possible continuation of the main rift. This route is the "French Aven", climbed on 29th and 31st July 2013. This climb closed in at the top, about 35m up.
Main way on (continued)
The right hand branch of Sala de los Bloques drops down to a point where the easiest route is to traverse right and down a slot into a lower passage. This ends at a large stal choke, which formed the original end of the cave.
An enlarged flat out crawl through stals, at the top of the choke against the right hand wall, leads to the start of the 1993 Extensions. This crawl can take a very strong draught at times.
Side passages at start of 1993 Extensions
These are reached by climbing up the far side of the steep slope which forms the inner side of the stal choke. At Easter 1994 this was described as being pushed to a bouldery chamber and a maze of rifts, chambers and chokes. At one point a calcited choke was seen. This was left unsurveyed. The series was entered again and surveyed in the summer, 2013 as batch 0075-13-07 (length 118m). Called Coral Rift Passage, the route passes through three tight "triangular squeezes" to a loose boulder choke, called Floose Boulder Choke. There is also a flowstone chamber called Wish You Were Here Chamber. All this area is in fact a large choke of huge boulders, probably the same as the Melted Candle Wax Chamber of Doom is formed in, the latter being at a much higher level.
Main way on (continued) - 1993 Extensions
Climbing down the stal slope from the crawl through the choke enters a stunning section of passage, liberally decorated with helectites and other formations. After about 100m the way is to climb down a steep slope and back up the other side.into a pit. Soon after a climb down reaches the sandy floored Main Junction.
From the Main Junction, a climb up and then back down enters a rift, with avens which close down at either end. However before the aven at the left hand (west) end, a traverse right enters continuing passage, until a 6m pitch is reached. This may be free-climbed via a crawl into a chamber nearby. At the base of the climb a small rift leads to a very steep, hading rift with a small, tight climb. A slight draught is present. The climb down was pushed at Easter 1994 for a further, unsurveyed 10m, until it became too tight. Half way down this rift an "aven" top can be seen. This drops as an 8m pitch to a tube spiralling down to a strongly draughting 5cm wide gap.
In the summer of 2012, the hading rift, 1m wide was tackled up and dropped (station 0 from 8th August 1993). Five metres below, a tiny hole was disto'd to a depth of 50m and this was later enlarged. Unfortunately, 15m down, the route narrowed in significantly and could not be followed. The disto'd point would be in Frog Passage in Torca de Regaton, quite close to an ascending muddy slope.
Straight on from Main Junction leads to a sand slope and the head of a 20(?)m pitch (Avalanche Pitch). The top of the pitch is best reached through a pit and arch under the slope on the left hand wall. Part way down there is a rebelay (hanger left, summer 2013). At the base, to the left is a steeply inclined sand and boulder slope. Immediately on the right, a fairly deep but loose hole was not descended. The slope descends to a narrow rift, through a couple of digs to a 10m high and 12m diameter chamber with a boulder floor and some interesting mud formations. The draught comes from a mud covered slope and a small slot which was dug to another chamber and passage which ended at a complete mud blockage after a very nice sediment bank and a cracked mud floor. The chambers were named in 2013 The Full Monty and The Dull Monty. The deepest point in this series is about 87m below the entrance.
To the right from the base of Avalanche Pitch leads to a magnificent formation - Eight Girls, One Octopus - just up a sandy slope, and then a short network of small passages, then a high rift chamber. There is a possible dig at one end and a climb at the other which will probably lead to the Music Box area.
A lined traverse (not rigged 2013) on the right hand wall over Avalanche Pitch has a tricky move half way round and then enters a well decorated passage to a draughting boulder choke in two passages. A descent down a steep boulder slope leads to a mud climb in a mucky, large chamber which has not been done. This series has lots of pretties including huge helictites.
The drop at the "end of the passage beyond the traverse" descends for 30m to a muddy choke in the floor.
The draughting dig at the right hand end of the sandy traverse was dug under an obstructing flake to a flat out, easy dig in sand.
At Easter 2013, in cold weather, significant numbers of Lesser & Greater Horseshoe Bats were seen scattered around the main passage. These are not usually seen in the cave whenever visted in the summer months.
Radon readings taken in 2012 around the big junction about 50m in from the entrance pitch were negligable, but this probably reflects the then strong inward cold-weather draught, and need repeating during warm weather conditions.
Most of the cave was resurveyed in 2012-2013.
On August 21st, 2019, Malcolm Foyle, on a "tourist trip" with the Wessex Cave Club, fell while using SRT equipment on the entrance pitch. After he had been brought to the surface by his team, Matienzo cavers gave some assistance by loaning a stretcher and providing extra manpower to bring him down the steep hillside to a 112 helicopter waiting in the field below. The helicopter took Malcolm to Valdecilla Hospital in Santander. He suffered severe knee ligament injuries.
References: Ullastre-Martorell J, 1975 (survey); Corrin J S
and Smith P, 1981; Smith P, 1981b (survey); anon., 1984 (logbook); material
in file; anon., 1993b (logbook); Neill Alasdair and Jackson Keith, 1993 (survey);
Corrin J, 1994a (survey and photo); Corrin Juan, 1995b (survey); anon., 1994a
(Easter logbook); anon., 1994b (logbook); Neill A, 1994; Corrin J, 1994b
(survey); García José León, 1997 (survey); anon., 2000b
(Easter logbook); anon., 2001a (Easter logbook); Corrin Juan, 2003a; anon.,
2003c (summer logbook); Corrin Juan, 2005; León García José, 2010 (survey and photos); anon., 2011d (summer logbook); anon., 2012a (January, February logbook); anon., 2012b (Easter logbook); anon., 2012d (summer logbook); anon., 2012e (autumn logbook); Corrin Juan, 2013a; anon., 2013b (Easter logbook); anon., 2013d (summer logbook); anon., 2015b (Easter logbook); anon., 2019b (Easter logbook); anon., 2019d (summer logbook)
Entrance pictures : yes : rescue 2019
Underground picture(s): formations : '93 Extensions 1 2 : scree slope & helictites : Easter 2004 : helictites, 2003 (MH) : miscellaneous, ISSA 2003
helictites (PS) : Summer 2011 : Easter 2012 - trip to Megabat : summer 2012 : autumn 2012 ASC Extension
Easter 2013 : Summer 2013 : Easter 2015 - Pee Pee Chamber area : Easter 2019
Videos : By Juan Corrin Entrance pitch from surface (2.1Mb)
Entrance pitch from underground (5.15Mb) Helictites in 93 Extension (3Mb)
Helictites in 93 Extension (3.4Mb) Formations in 93 Extension (2.7Mb)
Formations in 93 Extension (3Mb) Scree Run (2.2Mb) Climbing up entrance (4Mb)
Video by Torben Redder, 2012 summer (YouTube)
Passage sizes by Phil Papard, 2012 autumn (YouTube)
ASC Extension, Part 1 by Torben Redder, 2012 autumn (YouTube)
ASC Extension, Part 2 by Torben Redder, 2012 autumn (YouTube)
Some Easter 2013 explorations by Phil Papard (YouTube)
Further explorations, Easter 2013 by Torben Redder (YouTube)
Explorations around Pee Pee Chamber, Easter 2015 (YouTube)
Detailed Survey : from 1967: low res high res.
from 1994: 1:1000
2012 MegaBat extension and ASC Extension (both not drawn onto main survey)
New survey, Easter 2013 : survey summer 2013 : survey Easter 2015
Line Survey :
On area survey : on Cubija System survey; no detail
Survex files : after summer 2013 (Amended magnetic declination December 2013 to align with Eur79 grid and coordinates altered to fit ETRS89 datum, April 2014.)
on Cubija System area
Passage direction rose diagram: 30/6/2018