Lago Ercina

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Site list (GPS fixes)

Walks (GPS tracks) 

Coordinates used

LED projects:

 Lamp tests
 ISP isolators
 SMT boards

Expedition logs:

 1973, 1974, 1975,
 1976, 1977, 1979,
 1982, 1983, 1985,
 1986, 1987, 1988,
 1989, 2000, 2001,
 2002, 2003, 2004,
 2005, 2006, 2007,
 2008, 2009, 2010,
 2011, 2012, 2013,
 2014, 2015, 2016


 The Battle of
 El Mazuco

Expedition log, Summer 1976

A transcription of the Speleogroup/OUCC logbook.

This expedition, Forcau 76, was organized by Speleogroup and the Oxford University Cave Club, and had as its objective the Pozu de Vega El Forcau (now shown on Picos de Europa maps, 2km SSE of the sorthern tip of Lago de la Ercina, 30T 340.39 4790.42, alt. 1480m). This was partially explored by Speleogroup in 1975 with the French club SCAL.

See the expedition report » for additional details.

See the personnel list below for explanation of initials; italic initials in log show presumed primary author of text that follows, deduced from handwriting, etc.
29.06 MC: Left Winchester 21:00; collected extra 100m rope in Southampton. Joined boat queue at 21:50. Actually got onto the boat at 22:35; Southampton→Santander (Monte Toledo, Aznar Line). MC+BC+DT+ST.
30.06 MC: Full day on the boat including watching The Man Who Would Be King (and also The Adventurers (topical)?) films, sunbathing, etc. ST: Anzar Line meets with approval: First Class cabins (private shower, etc.) for just 21 each.
01.07 MC: Arrived Santander 07:35; cleared customs, etc., at 09:25. Arrived Posada (104 km) 11:05, Rales shortly after to arrange later accommodation, etc. Arrived lakes (after some overheating on the hill) 14:30. Raining; set up camp. After discussion decided to (1) start tackling Forcau, and (2) look for and survey Hoyo La Madre.

(1) [MC+ST] Sherpa’d ropes etc. up to Forcau and then proceeded to rig pitches 1→4. First obstacle was 10′ snow plug at the bottom of the first pitch: the whole of the entrance series visited was very cold. Four bolts added to the existing, one at the top of each pitch, so now pitches:

  1. Belay + Bolt
  2. 2 bolts (one above the other)
  3. 1 bolt before traverse + 1 on pitch
  4. 2 bolts (one each side of pitch head)

1¼ hours up to cave, 3 hours down it, ¾ hour walk down.

(2) [DT+BC] Searched for cave for two hours and after a roundabout walk found Río Casaño – small and steeply descending but not very interesting. Hoyo la Madre not found.

Forcau entrance – Bill

Forcau entrance – Bill

ST: A rather late start; Mike, Steve, Bill down Forcau at about 13:30. On this trip a second bolt was put at the top of the 5th pitch. There are abrasion problems near the bottom of this pitch due to a ledge. The rope was rigged on the 6th pitch with no extra bolts needed, short traverse line on the top part. On reaching the bottom of the 6th, the ladder for the 7th and rope for the 8th were taken along the rift. The ladder was rigged and descended, and the tackle bag with the rope was left at the foot of the 7th pitch.

The trip was successful and the only mistakes were a tackle bag dropped down the 6th and forgetting the hanger for the bolt on the 7th.

After the 6-hour trip we returned to the campsite to meet Dot, who had acquired very pink skin walking back from Forcau. We then drove down to Cangas de Onís and had an excellent meal of paella, trout, fresh fruit, and wine. Next stop was Posada – as it was Bill’s birthday Mike reluctantly agreed to get dragged into Becket, and Dot and Bill bopped. Lastly, on to Rales, had a drink in the bar, and went to bed in the hay loft of a barn. Variable amounts of sleep were obtained, but all were awoken by the repeated cries of a cockerel at dawn.

03.07 ST: We spent some time waiting for the bar to open in Rales, and then the same thing in Posada, but by about 10 a.m. we could wait no longer for the use of the loo in Posada and returned to Rales for this purpose. Wearing satisfied smiles we then proceeded to Barro beach via Posada and spent some time relaxing on the beach and in the bar.

Rales entrance – Bill

Rales entrance – Bill

Mike and Bill had an unsuccessful trip into Posada to get carbide, as the shops were shut. They returned to the beach for a while; then we drove to Rales to meet Victor and Maria del Mar, who accompanied Bill and Steve down Rales cave. This was remarkable for its superb gour pools.

Afterwards we returned to the lake, stopping on the way to refill the radiator again, and reached the campsite about 7:30 p.m. Prepared kit and food dump (for the bottom of pitch 6) for the next day, e.g., spent 20 minutes folding loo paper...

04.07 BC: Reveille at 08:45, and Bill makes macaroni cheese for breakfast in anticipation of the efforts to be required in the days Forcau trip. Arrive at the entrance after usual 1¼ hours in blistering heat to find that someone had stolen all the string they could lay their hands on – off bolt driver, hammer, + chocks.

Entrance pitches descended in ½ hour and on to the 7th pitch; ladder was bolted onto the anchor. Progress through the next few hundred meters of tight meandering stream passage was slow, but faster than through the previous rift. In particular a section of red/brown rock was v. tedious due to the projections coming out of the walls. Generally the passage was 2ft wide and over 15ft high with occasional pools.

A slight enlargement of the passage then leads to rapid progress as ones shoulders no longer rub against the passage walls.

Then a dry passage leads to a dry series littered with empty spanish packets of milk, etc. Shortly after regaining the streamway again (30m) one traverses above a pitch to another landing; out of the stream. A couple of bolts were hammered in, in anticipation of the descent of this (40m?) pitch.

The return to the bottom of pitch 7 (not carrying any tackle) only took 20 minutes, and here the roar of the waterfall was noticed. And at the bottom of pitch 6 the water had backed up a metre or so, covering some of our SRT tackle. On the 6th pitch Bill’s carbide demised, but the ascent was continued with Mike below on the same rope. This was repeated on the other pitches. Exit at 7pm. Found spring.

N.B. Near top of the 8th pitch the letters
were noted.  [This confirmed the identity of the cave, and the previous limit of exploration.]

05.07 DT: Up late ~ 11am due to very heavy rain. Straight to the bar for coffee and food – latter very nice but took a long time to arrive. Drove down to Cangas and then to Arriondas to find a garage. Killed time in bars in Arriondas while radiator leak was mended; it was still raining.

Drove up to Covadonga in very heavy rain, stopped to look at cave but it was raining too hard to leave the car. Continued drive to camp in even heavier rain. Spent evening in bar sheltering from rain. Warmed up with mulled wine while watching the rain.

It continued raining heavily throughout the night; estimate 5″ (125 mm) in last 36 hours. Lago Ercina has risen considerably.

06.07 DT: Another v. wet night so again up early. Breakfast at bar. First party MC + DT underground at ≈ 2:30 pm. Down to top of 5th pitch – put in new bolt to ensure free-hang. About 1 hour later ST & BC descended and collected bolting kit at top of 5th and continued down cave. MC + DT surveyed out and went to meet new arrivals (ML, DK, HW).

ST: Bill and Steve descended the 6th pitch rather eventfully. The hanger came off the bolt on 6c, causing Steve to fall 3ft and Bill to fall 1ft on 6b. Normality was soon resumed; we screwed back on the hanger and descended carefully. A new bolt is needed. The tackle bag containing 2 ropes + SRT gear was very troublesome in the rift.

The streamway was straightforward and we were soon at the 8th pitch. In order to investigate whether a free hang was possible, Steve descended 40 feet but found the pitch to be on a constant slope ≈85°. A bolt was therefore put next to the existing one at the pitch head. Rope rubs a bit.

The bottom of the pitch was wet and noisy, and a rift could be seen where the stream sumps briefly at the base. A little gardening was done with foot and hammer to clear the way for an 8-foot handline. Shortly afterwards a wet pitch of ≈15ft was reached. A bolt was put in, and the pitch descended by SRT. After this a series of cascades spiralling down was found, and we turned back.

The 8th pitch was done in tandem and we returned from the bottom to surface in 2½ hours, getting out at 10.30 pm (7 hours).

Lago Ercina – Bill

Lago Ercina – Bill

BC: Steve and Bill took the Reliant to Covadonga and investigated Cueva de la Campaña. After a few climbs up and down mud slopes a 5m pitch was reached which Steve free-climbed – Bill’s light not working too well. Steve found a few deep static pools and retired. Looks promising; a ½ hour trip.

MC:DT & MC took a brisk walk up to Forcau; descended and put a new bolt in at the head of pitch 6 in complicated rock.

DK: The new arrivals – Martin Laverty, Hilary Worth, and Dave Kelsey – took a leisurely stroll in search of caves through Las Reblagas and back via Vega La Cueva and Lago Enol. Unsuccessful.

BC: No sign of Jason et al. but V.O.P.S. arrive at 1 am. Surface streams and water in Forcau almost “normal”. Some water coming out of high level at Cueva Santa.

08.07 [VOPS (walkers) arrive 01:00.]

BC: Steve and Bill entered Forcau at 1:45 pm and reached their furthest point of exploration without incident at 3:45. The cascades were somewhat tight and we left our tackle and SRT gear after a few minutes of thrutching. Some of the squeezes are bypassed by climbs. After 100m the rift opened out and cascades become less frequesnt. Nice stream passage allows one to quickly walk to “el final en gran galería con afluentes”. i.e., the chamber with tributary reached by S.I.E.

Steve and Bill continued downstream without looking at the tributary and after even bigger passage reached the big deep blue sump (just 200m further on) 2½ hours after haveng entered the cave [total trip time 6¼ hours].

MC: MC and DK went down Forcau at 14:45, met the others shortly after the ‘Nylon’ (10th) pitch. [Bill obtained ‘bad taste joke of the year’ award, after delivering the worst possible news (of the sump) with a Cheshire Cat grin, by following this up with “Don’t look so disappointed!”].

MC & DK continued down to the sump; climbed 80′–90′ up into the rift (interesting climbing) without seeing the remotest possibility of a bypass. Retraced steps back to the chamber with the inlet and explored this through various complicated dry passages etc. until the stream had split into four and each one came to the bottom of a pitch (one 100′+). Exit uneventful despite lights fading; trip 7¼ hours.

DT: DT + HW spent a quite energetic couple of hours practising ‘change overs’ and other foreseeable difficulties which may arise, with the threat of a cold landing on the snowplug if anything went wrong.

ML: ML walked first towards Belbín and found 180′ shaft explored in 1963. Then looked at other holes all around lake, followed by looking in Cueva del Osu area (snow plug in open pot). Found a couple of possible grot holes but nothing draughting much except Osu which had howling wind emerging. Then over to Palomenu area – still no luck.

HGL 654H at Ercina

HGL 654H at Ercina

MC: Restock/recoup day. Down to Cangas for Petrol, food, Gaz, etc. (medium size gaz cylinder not available in Cangas or Arriondas). Restaurant lunch etc.

BC: BC, ST & ML went down Cueva de la Campaña, and put a 5m ladder on the pitch which Steve free-climbed on 7 July – not really long enough. A further 5m climb leads to a pool up to 2m deep. A small wall separates this pool from another which leads one to more muddy passage and then a clean boulder chamber. Very pretty black/orange rock. Way on not clear – several attempts made. One passage draughts strongly but is too tight.

We washed ourselves in Gueyu Reinazo resurgence on the drive up to the lakes. Martin found 10m more passage – an oxbox entered via a duck.

[No water coming from Cueva Santa high level.]

10.07 BC: Bill drives Viva to Covadonga where ML & DK get out to survey Cueva de la Campaña. Bill & Steve continue with Spanish lad to Cabelles (after meeting V.O.P.S.) and do the La Huelga through trip. This cave was surveyed during the 1965 B.S. expedition grade 3a (with no floor detail!). Much of it has not been surveyed. About 1km of passage surveyable. On return from Covadonga we let the car cool down and look at Trumbio entrance.

MC: Jason + 3 [JC, BM, Th.M, Tony M] arrive after wheel bearing breakdown in France – with the ALPEN and MARS BARS and other FOOD...!  Fresh sardines for all.

Campsite after the storm

Campsite after the storm

MC: Warm southerly gale at 03:00. First tent to go was Jason’s, followed later by Bill’s and Mike’s: quite dramatic. Come morning, a devastated campsite; with fog and rain. Bill, Martin, and one V.O.P.S. leave for Venta de Fresnedo; The Rest fester in the rain and later enjoy tent testing.

BC: BC & ML & Les (VOPS) leave at 12:00 and reach Suarias at 15:00. Look at down-valley Ojo Ceñal system and La Redonda sink. Then walk up to Cabañuca sink cave and through a couple of depressions to Cueva de Navaron sink. Night in barn (shared with rats!) in Suarias.

12.07 BC: Suarias party (Bill, Martin, Les) move on to Venta de Fresnedo; visit Toyu blocked resurgence, Cueva de los Marranos, Toyu sink, Comaria system, Cororigo System, La Huerta resurgence cave (3 hours walking). No water resurging from Cueva Santa high level; arrive back at the lakes 6pm-ish.

DK: MC & DK explored two holes above the Forcau 3rd and 5th pitches. The former was a nasty and tight rift with an 8′ drop, leading to halfway up the 3rd pitch after about 35m. The latter, after much acrobatics, didn’t go (and the 5th pitch is hereby named Acrobat Pitch).

DT: All people not yet been to bottom of Forcau decide to descend to the sump en masse – leading to a slow trip down (led by Steve with Dot, Jason, Tony, and Brian). First hint of trouble in rift when Brian’s wetsuit decides to fall apart. All reach sump safely when Tony’s light fails. Jason and Dot make own way out while Steve, Tony, and Brian do cold 3 hours surveying. On way back, pick up Jason and Dot who had got lost. Brian decided to test the breaking strain of his foot loop on the 5th pitch, leading to interesting moments. Eventually all out of the cave by 01:30 – a 12½ hour epic! 

Meet everyone else in 1st gully near lake with full rescue kit and all retire to campsite for a good ½ night’s sleep at 3 a.m.

13.07 MC: 8 went down to Cangas for shopping and meal. JC & Th.M remained at the campsite. 4 returned to the lakes after lunch to do washing, etc.; the others started a ‘quick game of Bridge’ & got back just after midnight. VOPS descend Forcau to the top of 8th pitch (2 people). Lose camera down a pot parallel to the 3rd pitch [later recovered].

ML: went walking, looked for Pozo Palomeru and Burdio de la Peña, and found the latter.

Lago Ercina campsite

Lago Ercina campsite

DT: DT & BM went for a walk and failed to find Hoyo la Madre. Returned by very circuitous route and came across unidentified cave previously found and marked by Spaniards just down-valley from lake.

MC: ST, HW, MC photographic trip to the top of the 8th pitch in Forcau. Very successful (if pics ‘come out’) – 70+ photies taken of bolts, pitches, pasage shapes, sand strata, etc. HW not slow up pitches, but had some interesting moments at the top of the 6th, etc.

ML: BC, DK, ML to Forcau sump (~3 hours?). Problems on entrance pitches where “someone” had heaped stones on the bottoms of ropes or otherwise tightened them giving very little slack for the attaching of descendeurs – in fact 6b had to be prusiked down by Bill. Martin had intended to use carbide through the rift but was foiled by the jet falling out and a huge screen of flame emerging from the hole – result caving on dip all the time.

On return surveyed inlet to avens and stream to a couple of cascades below 9th pitch. Returned with more carbide epics at food dump – Dave’s not working and Martin’s bursting into flame around the seal every now and then. Very slow exit up pitches since Martin’s ‘system’ disintegrated on the 6th causing excessive arm tiredness on 5th. Faster up 3rd, 2nd, & 1st. Surveying & exploring 3:15, 11 hour trip in total. Out 01:00 to a very clear moonlit night. Back at the lake 02:00.

15.07 MC: Another recovery day. 1 party down to Cangas; others play Bridge, etc. A trip to Trumbio by 4. “It’s big.”
16.07 MC & BC pack and leave at 2pm while the others prepare and clean gear for next day’s trip (not logged). MC & BC → Posada → Llanes → Posada → Rales – barn full of hay so back to Posada for night in a private house (150 pts) with a morning bath in coffee-coloured water ...
17.07 Drive towards Spain-France border after Tortillas in Acuario in Posada. Cross border about 7 pm. Campsite just north of Ste. Vincent Δ at about 9 pm. Odometer shows exactly 65,000 [245 miles from Posada according to log, but seems to be 295?].
Padirac train électrique

Padirac train électrique

Up at 9, check brakes etc. Car doesn’t start – flat battery – so try push start and then put on generator for ½ an hour.

Arrive Rocamadour area 4/5 pm. Look at entrance of Gouffre Lacaro, then “do” Padirac – 3F off on showing BEC membership card(!). Meet actress and friend (Jilly and Nicky) in Martel after a meal (16F50) who lend us some floor to sleep on.

19.07 Leave Martel 10:00; battery still NBG. Bank for Francs in Brive. Then Limoges, Poitiers, Angers, Rennes, St. Malo. Poor meal for 25F each. Night in a field.
20.07 Up at 06:30, looked around old town of St. Malo. Rain started. Cup of coffee (2F30!). To ferry (eventually) at 09:55. Battery still flat.

Ferry left St. Malo at about 11:30; cleared customs in Portsmouth (after spot-check) 9:25 pm (21:25). Back in Winchester (after a pint, of course) 22:00.

Personnel: Jason Clements, Bill Collis, Mike Cowlishaw, Dave Kelsey, Martin Laverty, Brian Matthews, Tony Moult, Theresa Moylan, Steve Tarran, Dot (Freya) Toft, Hilary Worth.

Other log details: Cueva Campaña survey data. Forcau survey data (mostly from 14.07 from ML & BC notes; ST notes, DT notes).  Sundry accounts and equipment details. Mileage and petrol records (1,433 miles total).  Separately, the Forcau rigging plan.

Exchange rates: 1 = 120 pts = 8.64 FF. Multiplier 1976→2011 was 5.6×.
Fuel: 26 pts (22p)/litre in Spain, 2F (23p)/litre in France (1.29 in 2011 ), 17p/litre in UK (0.94 in 2011 ).

Expeditions to the Picos de Europa and elsewhere since 1973.
Please e-mail Mike Cowlishaw ( or Bill Collis (
if you have any corrections, suggestions, etc.   See also the SpeleoTrove speleology section ».
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This page was last edited on 2016-12-28 by mfc.