Lago Ercina

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 El Mazuco

Expedition log, Easter and Summer 1977

A summary and index of the Speleogroup logbooks.

1977 saw two Speleogroup expeditions to Spain; one, a reconnaissance expedition at Easter, and the other (objective the Sima de Garma Ciega) in the Summer.


01.04 Temporary headquarters: St. Georges Drive, London. Expedition launched with Taylor’s ’71 Special Reserve.
02.04 Some hours flight delays, Bilbao at 18:30. A wet Castro Urdiales and meal at Paris. Camped above cave at 01:30.
03.04 Down Sangazo cave (as named by OUCC, real name in 2001 log) 10:30 ad explored to just beyond previously unknown inlet. Forced to curtail exploration by failing carbide lamps.  Special Paella lunch at Paris, then west and south towards San Pedro.  Rental car not quite up to off-road exploration of some interesting Forest-of-Dean-style sinks caused a 3-hour delay; San Pedro reached at 20:00; Spanish Cavers (QUAD-C) already there.
04.04 Lost the Spaniards, so started up towards Garma Ciega at 11:15.  In snow once over 800m, with snow falling. Reached cave by 13:15, soon met by Spaniards by gear by tractor. Swapped caving rope samples.  Returned to San Pedro in an hour, then off to Suarías via Unquerra.  Hayloft over noisy mule for the night.
05.04 Up the gorge to Venta de Fresnedo via La Hermida; potential resurgence (Cueva de los Marranos) didn’t go. Looked at Cueva del Toyo, but more water than Porth yr Ogof in flood and pitch far too wet.  Slow return to Suarías via Panes. A friend of Bill is 16 today.
06.04 Perfect weather; move east to Matienzo. Huge depression and sinks.  On to Riva then up the Asón valley via Arredondo to Cueva la Cuvera; a resurgence but too deep to follow. Sinks above unpromising (blocked with mud/sand). Meet Speleo Club de Paris members at the Col de Asón; they had been exploring the Gandara source.
On to Ramales de la Victoria (fine meal for 404pts) and back up to San Pedro for a night in a field.
07.04 A political start with Spanish cavers. Then up the hill to sinks noted on 04.04] (not clear where; route was around the Sumidero de Cellagua depression and Pico Tejes, but sinks may have been seen on the way down).  Found one small one then a better one, ‘Cueva del Mazo Chico’, about 50m+; surveyed to grade 2b (see log). Another with a snow plug had roar of water beneath.
Meet Quad C again at camp; they had discovered that the earlier ‘Garma Ciega entrance’; was in fact wrong (despite telephone cables, etc.), but had found the right one.  Long wait for meal in the San Pedro bar, then off to find accommodation.
Ramales full, Santillaña closed, so on to Rales then towards El Mazuco. Halted by cavers from Oviedo (literally) on the road, who give us a room for the night.
08.04 Posada Acuario & Café Moderno for a late breakfast. Then east to Ribadesella and drove through the Cueva Tunel de la Caretera to Cuevas.  Afterwards, looked at depressions near La Vita (“maps hopelessly wrong”).
Back to Panes for the evening and The Barn at Rales for the night.
09.04 Attempted to drive up to Los Lagos, but forced to abandon car below lake Enol due to traffic unable to negotiate ice. 10cm snow around.  Got to Ercina in daylight, then retreated to Cangas. To Amieva, then Calabrez to big depression, Cuevona, near Cueva Rosa, with interesting sink. Back to Posoda (Acuario, Becket, La Plaza).
10.04 (Easter day.) Back to Cueva Rosa area again and explored the sink cave for ~0.5km to wet deep duck. Obviously explored and surveyed previously. Next to Moria sink; impenetrable. Round to the resurgence, Tito Bustillo (now show cave). Back to Posada and Rales.
11.04 Departed east. Campsite closed at Castro Urdiales, so back to Laredo.  Huge depression just east of Laredo, near the (old) road.  Eat well, but both suffer shellfish(?) poisoning.
12.04 Bilbao for the flight to UK.

Summer – Sima de Garma Ciega

26.07 Heathrow to Bilbao. Car hire transfer into Bilbao, then 1cwt of gear transferred in yellow Seat 127, off by 19:15, San Pedro (near Ramales) 21:15. Pete/Mark/Phil already there.
27.07 Pouring rain, slow start, bolted initial pitches in hard limestone starting 12:50. Second wave (Bill & Mark) down at 19:30, all out by 23:00 and back to camp by 01:00.
Ropes on first carry: 35m (pitch 1), the 4 bags: 92m, ?m, 80m, 35m + 30m + 15m. Mixed Edelrid & Marlow. 3 bolting kits, thimbles, rope protectors (6+). Second carry: 45m Marlow, 1 tent, 1 bottle wine. Details of pitches in Log.
28.07 Surface exploration and recovery in more rain. 3 resurgences (at K3, K6) examined. Cueva La Cubera (left bank), Punta el Praduco (opposite, 400m upstream), and Las Fuentes (at K6.3). M&Bill march up hill to camp at cave, others in Ramales.
29.07 Rain all day again. Fabada breakfast, then down the cave at 10:00.  General exploration (Spanish campsite, etc.), out after 5.5hrs.  Down to Ramales for a recovery evening, while others do the reverse ready for caving the following day.  (Technical details in log; Pitch 6, 6m, rigged.)
30.07 Ramales for search & shopping; San Pedro to charge lamps. Others have good trip in cave (progress beyond ‘point 12’, much abandoned rope found), but leave tent door open so Alpen, eggs, etc. eaten by dogs...
31.07 Sunday, so join in festivities. Meet J. L. Garcia in Ramales and Antonio in San Pedro.
01.08 Phil and Antonio descend cave past Salle Blanche, into big chambers, a 20-hour trip.  Mike and Bill both ill – reach cave but do not descend and wait for Phil and Antonio; others look for potholes on a different mountain.
02.08 Phil and Antonio surface at 09:00. General shopping and housekeeping, and return via Matienzo to meet MUSS, Tony Waltham, etc.
03.08 Pete and Mark descend to −750m, 19-hour trip.  Hydro-geology; Garma Ciega possible resurgences, etc. Back to Matienzo to recruit some helpers.
04.08 Strain amongst the personnel, despite two fresh helpers (Steve and Alan). 6-hour detackling trip. “It’s the best SRT rigged cave we’ve been in” (Steve’s entry in log).  Fabada at 01:00.

Easter: Bill Collis, Mike Cowlishaw, QUAD-C
Summer: Bill Collis, Mike Cowlishaw, Pete Hiscock, Mark Falkner, Phil Collett. Later joined by, Steve Foster and Alan Trevarthen (MUSS/PCG).

Other log details:

  • Exchange rate 115.61pts:1GBP.
  • Easter: Surveys of sink cave above San Pedro and Cuevas Tunel.

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 2021-09-27 by mfc.