2019 Summary

A distinct lack of enthusiasm from people for writing up the expedition….. A post trip summary follows:

The Tresviso expedition returned back to the UK last week and the following is a brief summary:

Cueva del Nacimiento – Parting Friends

In the entrance series of Nacimiento is an area called the Road to Wigan Pier and at the end if a waterfall climb to the Parting Friends sump.  This was originally discovered in the late 80’s and later dived by Gavin Newman / Phil Short, during the filming of ‘Extreme Lives – Road to Certain Death’.  Unfortunately, no survey exists, but the sump was described as around 150m, still continuing and, unlike a lot of the other sumps in Nacimiento, was not at depth.

It took nearly 4 days to rig the stream ready for the dive.  The grade 2 survey of the approaching passage proved to be misleading… 9m up pitches, were actually preceded by 60m of steep ramps, aid traverses and bolt climbs, all while stood next to (or under) a raging torrent of water. 

Cueva del Nacimiento – Cascade Inlet, Joe Daniels (2019)

Eventually, all was set up and the divers, Rob Middleton and Joe Daniels, could attack the sump.

Dive 1 – passed after 25m (at -6m depth) to 30m of streamway and climbs.  Second sump, 4m diameter passage, 115m line laid

Dive 2 – sump 2 to -165m

Dive 3 – way on found, passing believed previous limit to large airbell.  Sump continues in typical Nacimiento ramp style passage to another large airbell.  Fourth sump found and way on in open sump passage.

Total length of passage 439m.

Cueva del Nacimiento, Parting Friends Sump 1, Arwel Roberts (2019)

The day after the final dive, the rain came in and flooded us out of the cave for 3 days.  A lot of equipment lost and the crucial dinghy to get across the entrance lake washed away, probably now wrapped round a turbine at the hydro-electric plant.

Cueva del Nacimiento entrance (post flood), Derek Cousins (2019)

Cueva de la Marniosa – Free Willy

In the upper series of Marniosa, before the streamway is encountered, is a section of cave called Extra Caverns.  Discovered in the late 70’s a number of leads and unclimbed avens exist.  Phil and Howard attacked the avens over a number of trips.  At the very far end, two small 5m avens lead to the same connection at the top (subsequently bypassed without the need for any climbing) leading to a tight rift and a draughting immature streamway.  2 further avens  (approx.. 10m) were found at the end but not attempted. 

Further back in the main passage, an obvious wet aven was scaled for 10m to where it split into 3 further ‘avens’.  The left hand route led up for a further 20m to a narrowing rift, with limited potential.  The first right hand route led, after another 5m, to a tight upwards squeeze, passed by Leo to around 5m of passage and another 15m aven.  The final route from the junction leads back out of the main aven, but was only scaled for another 2-3m in poor rock, before time ran out.  This remains the most promising lead, with an obvious lip a further 5m up.

Cueva del la Marniosa – new discoveries

On a final surveying trip, Phil and Alastair ‘stumbled’ upon two exciting new discoveries in the upstream Marniosa streamway.  Although not shown in the 70’s survey an obvious bend in the streamway has a dark space above.  A 3m climb up lead to a huge new chamber, 50m x 20m x 20m, with a large 35m aven at one end and a high level route at the other. 

Just at the bottom of the same climb up to the chamber, was a large boulder hiding a second streamway / inlet, entering the main stream.  This was pushed for around 50m and still continues.  The high level route in the chamber was revisited and extended for another 50m in large passage to a ramp down, probably into the same new streamway.

Silvestre Pot – Marniosa – First through trip

The first through trip from Silvestre Pot to Marniosa was complete by 2 teams during the expedition, before the Silvestre section was derigged – see early post for a write up.

Silvestre Pot – Sumps

Two sumps in the upper levels of Silvestre were dived.  Bob’s Crusade sump was dived for 32m (-6m depth) to an airbell, tight continuation possible but not appealing.  The Wet Willy sump was passed after 3m to a second sump aftetr 40m of passage.  Sump 2 is largely ‘organic’ and was abandoned after 2m.

Andara, Lisa Boore (2019)

Tresviso 2019

Andara (Eastern Massif) viewed from Tresadura (looking South) (Phil Walker)

The 2019 expedition is only 5 weeks away. Hopefully some interesting blog posts will be created, but firstly, as per previous years, a bit of a brief overview of expedition:

Overview & brief history:
The Picos de Europa is a range of mountains 20km inland from the northern coast of Spain, forming a westerly extension of the Cantabrian Mountains. It consists of three main areas, the Western, Central and Eastern Massifs.

  • The Western Massif is to the west of the Rio Cares and has been explored by a selection of clubs including Oxford University Caving Club (OUCC), Seccion de Espeleologia Ingenieros Industriales (SEII), York University Cave and Pothole Club (YUCPC), Sociedad de Espeleologia Geologicas (SEG) and Speleo Club de Paris (SCP). This now includes the area under exploration as part of the Ario Caves Project.
  • The Central Massif is between the Cares Gorge and the Rio Duje and has been mainly explored by the Speleo Club de Seine (SCS).
  • The Eastern Massif is to the East of the Rio Duje. Lancaster University Speleological Society (LUSS) were exploring the Eastern Massif from the early seventies to 1987 with the help of SEII.

It was the Eastern Massif (or Andara) that drew the attention of LUSS in the early 1970s. In the early years exploration was mounted from the mountain village of Tresviso and exploration was dominated by the resurgence cave Cueva del Nacimiento (Cueva del Agua) located at the foot of the mountain range. The resurgence flows into a canal that contours the Urdon gorge with an average flow of 2 m3/s and the cave behind the resurgence leads to >12 km of surveyed passage and a height gain of over +534m.

The catchment is some 40 km3 and includes caves such as Torca Jou Sin Tierre (CS-9) at -1203m deep and Torca del Cueto de Los Senderos (Sima 56) at -1169m deep.

Morning Chamber, Cueva de La Marniosa (Joe Daniels)


In the late 70’s LUSS pushed Cueva del Nacimiento to around the 11km and +300m mark, but after several years the cave was abandoned as all the major routes sumped and no continuation could be found. LUSS then turned their attention to the Andara region higher up the mountain range and sought caves that would drop into the Nacimiento system and hopefully create a record-breaking >1500m traverse. They found a number of deep caves around this ‘top camp’ area; Sara, Tere, Flowerpot, Dosser’s Delight and Sima 56 were all pushed to respectable depths but a
connection remained elusive.


The discovery of newer and deeper systems, plus improved GPS, have changed the figures slightly but a connection between the deep potholes and resurgence would create; a cave in the top 10 worlds’ deepest, deepest in Spain and potentially one of the the deepest underground traverses in the world.

Top EntranceAreaAlt(m)Current Depth (m)Vertical Range (m)
S-33 Torca de la Hendida Samelar2100-4521620
CS-9 Torca Jou Sin Tierre Cueto Senderos 2074 -12031594
Sima 56 Cueto de Los Senderos Cueto Senderos 1975 -11691495
T82 Karen – 2.6 Sara Grajal (Sara depression) 1880 -5911400
T145 – Pozo Castillo Mazarassa 1870 -3091390
2.24 Tere Grajal (Sara depression) 1820-7921340
FT39 Compromisso Mazarassa 1820-3131340
T169 Flowerpot Pico Boro 1785-7231305
T173 Dossers Delight Pico Boro 1706-8311226
T190 Septrin Pico Boro 1696-1801216
3.2 Torca Branarredonda (Fallen Bear) Samelar 1589-4561109
T510 Cueva Entre Cuetos Sierra del a Corta 1305-117825
T69 – Pozo Motilla Sierra del a Corta 1248-70768

Table: Potential depth if connected to Cueva del Nacimiento (2017).

Note: There are at > 70 sites at higher altitude than CS-9 that would surpass -1600m deep through trip, with some close to -1800m depth.

Survex – Mountain range looking E-W

Expedition Dates
• 31 st August 2019 to 14th September 2019 – main expedition dates

Objectives
The expedition has several goals. The following are a few primary objectives:

Cueva del Nacimiento

  • Jurassic World – The Sandy dig, draughting lead, now only an hour from camp
  • Pina Colada Bypass – calcite aven to climb
  • Joe’s Crack – continuing shaft behind Death Race camp.
  • Teeth of Satan – Wet Aven – +30m aven with draft and calcite squeeze, requires enlarging.
  • Dan’s Big Room – unexplored section of maze in area of Dan’s Big Room, Peanut Chamber and Winter Gardens
  • Parting Friends – a dive of the Parting Friends sump is planned.
Pena Coloada Sump (CUeva del Nacmiento) (Rob MIddleton)

Cueva de la Marniosa

  • Beyond Sump 2 – undescended 6m pitch
  • T20A Silvestre – Marniosa – first through trip to be completed
  • T20A Silvestre – upstream leads, heading toward the Valdelafuente

Secondary Objectives:
Time and resources permitting there are several secondary objectives that will be attempted:

Downstream Marniosa (Joe Daniels)


Sistema Castillo
A large mine and natural cave complex in the Minas de Mazarrasa area. Pozo del Castillo series was explored to – 292m depth in 1983, with either a howling draft or roaring waterfall beyond a constriction at the limit. The potential of the cave is significant but currently a collapse prevents getting to the end. Pozo Natacha series ends at -309m depth and is close to the same point in Castillo.

  • Pozo Del Castillo – shoring and bypass of rock collapse Castillo remains a major lead, if we can get past the blockage! In 2018 the snow level had dropped and possible to get into the next section.
  • Pozo del Castillo – other entrances. FT16 entrance snow plug would appear to be the same blockage in lower Castillo passage. Snow plugs are reported further into the cave, so another entrance must exist!
  • Pozo del Castillo – surveying of Natacha upper series and locating possible surface entrance,


Valdelafuente / Sobra Valley

  • Re-locate draughting surface entrance on Valdelafuente, close to 80m aven beyond Sump 1 in Cueva del Marniosa,
  • Yorkshire Inlet in Cueva del Marniosa. Exploration of col above aven

Sierra del a Corta

Above the furthest reaches in Nacimiento is the Sierra del Corta. A heavily wooded area with a number of promising leads, that could potentially drop into Nacimiento and provide an easier route into the back-end to aid exploration at the far reaches.

  • T554 – large 100m shaft on the Sierra del a Corta, this requires some digging at the bottom,
  • Al2 – a drafting shaft not yet bottomed. Jurassic World in Nacimiento appears to be heading directly towards this site,
  • T294 Oh What Pot (La Gobia) – continuing passage,
  • Surface prospecting close to vicinity of Terror Firma in Nacimiento. Terror Firma is only 40m vertically and 200m horizontally from some parts of the surface in the Sierra del a Corta region.

Other

  • Locate and descend FT43, this draughts strongly. It is almost directly above Boulder Chamber in T87 Mazarrasa and would provide bypass to collapse at T87 entrance.
  • Prospecting on Hoyo Oscuro and Hoyo Evangalista. Highest entrances on the mountain range.
  • Mine 2.32a – there is large unexplored level (with tram lines) leading to unexplored passage.
M6 Toll Bypass, Cueva del Nacimiento (Arwel Roberts)

Article on recent expeditions published

The 2018 expedition is now only 4 weeks away. A few red tape problems have now been resolved and everything is set, including last minute equipment orders, turning over the shed looking for old equipment and herding everyone into position.

The latest edition of Descent (No 263 – Aug/Sep 2018) includes an article on Tresviso exploration, giving an overview of the recent work by the team, and is well worth seeking out a copy. Available from 4th August.

https://www.wildplaces.co.uk/

Tresviso 2018

Prospecting for caves (Sam Deeley)

Expedition Dates

  • 1st September to 15th September 2018 – main expedition dates

Objectives

The expedition has a number of goals.  The following are a few primary objectives:

Cueva del Nacimiento

  • Jurassic World – Terror Firma – multiple avens and climbs,
  • Pina Colada Bypass – a 3-10m rift leads off from the Pina Colada sump.
  • Joe’s Crack – un-descended shaft behind Death Race camp.
  • Teeth of Satan – Wet Aven – +30m aven with draft and calcite squeeze, requires enlarging.
  • Dan’s Big Room – unexplored section of maze in area of Dan’s Big Room and Winter Gardens
  • Parting Friends – a dive of the Parting Friends sump is planned.

DR traverse (Chris Jones)

Cueva de la Marniosa

  • Beyond Sump 2 – a dive of sump 2 and exploration beyond is planned

Pico Boro (SUSS)

SUSS are also involved and will take on responsibility for exploring either  Flowerpot on the Pico Boro area.

  • FlowerPot – re-rigging and exploration of leads
  • Surface sweep and logging of entrances in Sara Depression (around camp)
  • Surface sweep and logging of entrances in Pico Boro area


Secondary Objectives:

Time and resources permitting there are a number of secondary objectives that will be attempted:

Sistema Castillo

A large mine and natural cave complex in the Minas de Mazarrasa area.  Pozo del Castillo series was explored to -292m depth in 1983, with either a howling draft or roaring waterfall beyond a constriction at the limit.  The potential of the cave is significant but currently a collapse prevents getting to the end. Pozo Natacha series ends at -309m depth and is close to the same point in Castillo.

  • Pozo Del Castillo shoring and bypass of rock collapse Castillo remains a major lead, if we can get past the blockage!
  • Pozo del Castillo – other entrances. FT16 entrance snow plug would appear to be the same blockage in lower Castillo passage.  Snow plugs are reported further into the cave, so another entrance must exist!
  • Pozo del Castillo – surveying of Natacha upper series and locating possible surface entrance,
  • Pozo del Castillo Natacha 1983 series. Attempt to get small, skinny person through current limit, otherwise derig and survey.

Pozo Castillo (Chris Jones)

Valdelafuente / Sobra Valley

  • Re-locate draughting surface entrance on Valdelafuente, close to 80m aven beyond Sump 1 in Cueva del Marniosa,
  • T20 (Sobra Valley) – sandstone sink above Hall of the Mountain King in Cueva del Marniosa,
  • Yorkshire Inlet in Cueva del Marniosa. Exploration of col above aven (also close to T20),
  • Upstream series in Cueva del Marniosa. Large black voids above the streamway,  if leads head to the South this is up the Valdelafuente

Sierra del a Corta

Above the furthest reaches in Nacimiento is the Sierra del Corta.  A heavily wooded area with a number of promising leads, that could potentially drop into Nacimiento and provide an easier route into the back-end to aid exploration at the far reaches.

  • T554large 100m shaft on the Sierra del a Corta, this requires some digging at the bottom,
  • Al2a drafting shaft not yet bottomed.  Jurassic World in Nacimiento appears to be heading directly towards this site,
  • T294 Oh What Pot (La Gobia) – continuing passage,
  • Surface prospecting close to vicinity of Terror Firma in NacimientoTerror Firma is only 40m vertically and 200m horizontally from some parts of the surface in the Sierra del a Corta region.

Other

  • Locate and survey General This may be another way into T87 Mazarrasa, bypassing entrance collapse. (most likely T88 Suerte or T89.  T88 draughts strongly at junction inside)
  • Locate and descend FT43, this draughts strongly. It is almost directly above Boulder Chamber in T87 Mazarrasa and would provide bypass to collapse at T87 entrance.
  • Surveying of Nacimiento top entrance series. There are a number of unsurveyed and minor leads in the area,
  • Prospecting on Hoyo Oscuro and Hoyo Evangalista. Highest entrances on the mountain range.
  • Mine 2.32a – there is large unexplored level (with tram lines) leading to unexplored passage.

2017 Summary

Cueva del Nacimiento – Jurassic World – Terror Firma

The ‘final’ aven at the end of the cave was climbed to over 40m, a split in the aven was followed to a new height of 534m above the entrance, but closed down.  The second aven remains unclimbed and is ongoing 

Cueva del Nacimiento – Jurassic World – Pterodactyl Crumble

Another aven at the end of the cave was explored upwards before reaching horizontal passage for another 60m, then finally closing down. 

Cueva del Nacimiento – Death Race 2000 – Joe’s Crack

Initial constriction was passed and the passage continues down another 35m, to head of undescended 12m pitch.  The passage heads under the Death Race chamber, toward the Death Race pitches.

Cueva del Nacimiento – Teeth of Satan – Wet Aven

The Wet Aven was not attempted on this trip, in part due to 2 trips getting lost on the way to the far end and running out of time to climb.

Cueva del Nacimiento – Other

180m of passage found near Death Race passage.

A new aven (+30m) found near P Chamber in Death Race passage, continues.

Cueva del La Marniosa

Sump 1 was dived and the 80m aven beyond was climbed to approx. 47m.  The rock is extremely poor and no obvious continuations could be seen at the top of the aven, using powerful lights.

The Marniosa team diverted attention to trying to dive Sump 2,  an undived sump, discovered in 1987 and unvisited since.  A rather ambitious trip saw two cavers reach sump 2 and allowed one diver to pass sump 2 (30m long t 5m depth) to surface in stream passages.  A further 40m of cave was explored and still continues, before safety concerns forced a retreat.

 Pozo Del Castillo.

Pozo Castillo continues to be surveyed (2km +) and leads explored, attempting to bypass the 1987 snow collapse.  The rediscovery of FT16 and the lower snow levels, allowed further progress in the system, but a sump was encountered at -110m.

Pozo Natacha (a series of pitches in Castillo, rather than a separate cave) was pushed past it’s 1983 limit, down a tight right to the head of a tight 20m pitch.  This pitch head would need serious enlargement before further exploration can continue.

Other exploration

Torca del Carneros was (re)discovered and surveyed.  This lies on La Mesa, above Tresviso, and probably would be connected to caves draining away from Tresviso toward the San Esteban valley.

Fallen Bear was also rigged ready for further exploration in 2018.  The bulk of the cave is a steeply descending ramp, similar to Nacimiento, and contains a number of leads of potential.

Summary:

In total over 2km of cave was surveyed in 2017.  Exploration of Nacimiento continues and has now pushed the height to over 534m from the entrance.  A logistical challenge that is not proving to get any easier, despite fixed camps toward the end of the cave.  Trips to the far end require 4-5 nights of camping, and advanced camps at the far (far) end now need to be considered.  Passing the second sump in Marniosa is a major achievement and unexpectedly has surfaced in passage heading away from Nacimiento and into the mountain, possible towards a hypotheses trunk route that may also feed the upstream sump in Nacimiento.  The rigging of Fallen Bear, and discovery of some new leads, opens up further possibilities of closer deeper systems lying between Nacimiento and the deep potholes high on the mountain.

Quick Updates

More details to follow but a quick taster

Cueva del Nacimiento – new height reached at back end of cave

Fallen Bear – new leads discovered

Torca de la Carneros – possible leads on hill above Tresviso

Cueva de la Marniosa – Sump 2 (previously undived) passed last night…

 

Oh and Pozo Castillo – still collapsed

 

Second trip down Agua, Joe’s Crack

Alex again,
Phil and myself embarked on another three day trip down Agua on Saturday 15th. With significantly lighter bags, the trip to Death Race was much quicker than the first time. I was able to appreciate the cave more on this trip, the trip to Death Race really is a good varied day of caving. We met Dan and Dave near Death Race heading out for a night of exploring.
The next day the plan was to push Joe’s Crack, the tight rift I had looked at previously. Phil decided this last was too tight for him, so it was up to me to bolt the traverse until it became wide enough to abseil down to the bottom of the rift.
The bottom of the rift widens slightly and the floor dips down below the traverse heading back towards Death Race. Part way along there is an opening into a much wider rift, estimated at 4m across, into which a pitch could be dropped, this was not done on this trip but is an open lead. The small rift turned a corner and chokes.
Returning up the pitch to get the survey kit turned out to be fairly unpleasant, due to the very tight nature of the pitch. Phil reaffirmed his belief that he wouldn’t fit, leaving me to do the survey alone. A shot down the large passage revealed it is at least 12.5m deep, so worth returning to by anyone keen to go down the tight pitch.
Left Death Race the day after in good time, including Phil doing the sump five times to get some video footage of it. Good effort, once is enough for me. Shame the video turned out to be pretty rubbish.
Thanks to Phil for the trip and making the necessary cups of tea throughout the day.

Combine Harvester Traverse

Sam and myself went down Agua looking for a traverse discovered by Derek the year before; the traverse starts at the top of Boulder Hall, it was not fully crossed so the far side was new passage. This excursion have me an opportunity to bolt and rig a traverse for the first time.
The traverse went well, the last section involved balancing off a bridge that seems to be entirely made of mud, I was glad of the bolts and rope at this point. At the far and was a constriction, I squeezed up this into the a small area. To one side there is a further squeeze and there appears to be a large section beyond it. Unfortunately we were out of bolts by this point, so we had to leave it for another day.
That evening we were discussing the day in the hut, and we had to decide on a name for the traverse. Chris suggested “Combine Harvester Traverse” as a few days before we had sung it down at Death Race, I had to teach Chris the words, and the name has stuck. Brilliant.
Thanks to Sam for the trip and his instruction on bolting.

Trip to Death Race

Alex again, feeling good if tired.
After going across the lake on the leaky boat again, we picked up the bags from where we stopped the day before, and headed on into the cave, psyched up for the biggest caving trip I’ve attempted.
The trip in was hard but good fun, with some really varied caving. Going up the ramps was hard work, especially carrying a bag of kit. The hole in the wall was impressive, and the duck was a bit grim, but on the whole a really good trip.
Finally I spotted camp, and dropped down the final climb. I was definitely ready for a rest and some hot food. However it became clear that neither of us knew how to operate the petrol stove, and after an hour of trial and error, we gave up and used the lunch stove to make some cous cous. I then attempted some bolting down Joe’s Crack, turns out it is harder than I expected. Then Chris and Hannah turned up, Chris fixed the stove and we had some food. The  it was time for my first night camping underground, and it was much nicer than I expected.
The next day we headed on, up some pitches; I quickly got stuck in a hole. Then I came across a down pitch where the rope was caught, so time for some down prussicking on to the traverses. Which are scary (for more detail on this point, ask Dave). After much terror we reached the other side, and we were away. After a few hours of good sporting caving, we reached a very slippery, muddy pitch, which was a sod. At the top of this was some of the most amazing passage I have seen. The difficulty here was not damaging any fomations when passing through. We then started scouting for interesting leads, and stopped very near the end of the cave. We used the stove to make some lukewarm tea and noodles, before we got ready to go. Dave then started his aid climb, whilst I sat on a ledge belaying for a good few hours, which was fairly cold, made much better by the down jacket and warm tea. After several hours it appeared that Dave had made good progress, and that the climb was still going.
The climb was named Terror-firma by Dave, the climb went up around 25m to a narrower bit; it is a promising lead, and Dave intends to return to push it further.
We made our way back to camp, over the traverses (still scary), for some sleep before heading out.
We were relived to find a new boat at the lake, and I overjoyed to find some beer stashed by the entrance. Best tasting beer I’ve had in a while.
Thanks to everyone for a good trip.