Lago Ercina

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Site list (GPS fixes) Walks (GPS tracks)  Video clips Panoramas

Coordinates used

Electronic projects:

 Bat detector
 Lamp tests
 µ-controlled lamp
 SEPIC-based lamp
 ISP isolators
 Making SMT boards

Expedition logs:

  Spain 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, 2017, 2018,
  2019, 2020, 2021,
  2022, 2023
  New England


 The Battle of
 El Mazuco

Trumbio 1974/75

Trumbio 1974/75

Name: Cueva del Trumbio

Location: Close to road between Covadonga and Los Lagos

GPS: N43°17'43" W5°01'56"

UTM: 30T 335.26 4795.82



Surveys: OUCC 1974/5 » – entrance chambers, by Bill Collis

Memoria Cueva del Trumbio – Sierra de Covadonga 2012 – A. D. GEMA

Description: OUCC Proc. 7: » “Following the path from the ruin marked on the map as ‘El Trumbo’ one soon finds a steep blind valley drained by a large dry cave entrance. The bedding plane entrance soon becomes wider and then narrower and higher and after a couple of short drops one reaches a loin pitch. The cave changes substantially from here, becoming enormous. A stream rises from the boulder floor and echoes throughout the vast chamber. Then the cave abruptly comes to an end and the stream sumps. There are no significant side passages.

This is a very pleasant cave and, although dry, is very clean. It probably takes a stream from the resurgence up the valley in wet weather. The rock is as smooth as marble and as pretty, though there are few formations. In 1975 the French S.C.A.L. group were found to have explored and surveyed Trumbio in 1964 – comparison of surveys showed substantial agreement.”

Rises at Güeyo Reinazo (traced in 1964).  Dived in 1985 by NPC » and in 1986 by OUCC ».  Neither diver passed a possible slot under unstable boulders.

2011 extensions, from Jose Ramón Saiz Barreda, of the Asociación deportiva Gema:

2012.01.16, slightly edited:

Once at the terminal sump our powerful spotlamps highlighted the existence of a gallery hung 40m(!) above the sump. 8 hours later we put foot in an enormous oxbow, 50 meters in height.  After six months we have explored 10 km of galleries, surveyed 9.2 km, some even larger than the great Gallery above the sump.

A spectacular collector has been explored until near the cave of Reinazo (−300 meters deep), waterfalls up to 40 meters, 90 m wide rooms, and a multitude of formations form parts of this spectacular cave that had never been dreamed of.


Estamos realizando estos dias un informe relativamente detallado para la federacion española de espeleología, cuando lo termine os lo remitiré.  Nuestro club se llama Asociación deportiva Gema, como te dije somos de Gijon, un club solo con cinco o seis personas activas habitualmente.

La revisión del Trumbio comenzó en esta primavera y los trabajos continuaron hasta noviembre, explorados 10 Kms y topografiados 9.2 Kms.

La cueva posee 4 0 5 niveles, dependiendo de la zona. el final conocido aguas abajo está apenas 400 metros de distancia y practicamente a nivel del sifón de los Güeyos del Reinazo, un enorme sifón y una red laberintica pone de momento fin en este sector. Varias escaladas quedan pendientes en esta zona.  Hacia la mitad de la cueva llega un rio del Sur-Oeste, que pronto se sifona. este va a ser buceado en los proximos dias.  Restan bastantes galerías secundarias por explorar y topografiar, ha sido localizado un caos de bloques con fuerte corriene de aire que parece dar acceso a la red superior, “camino de Comeya” pendiente de una laboriosa desostrucción, que sin duda vamos a realizar.

2012/13 extensions, from Jose Ramón Saiz Barreda (2014.01.20)

Nowadays, we have surveyed a few more of 11kms. We have dived a sump of a tributary (Sifón de los Cobardes) where we have gone down 19 meters deep, but we couldn’t continue because the sump was very dirty and tight.

After the Vivac’s room (the start of the final collector), we have made several climbs until a room that it’s almost outside. Here, a lot of roots of trees hang of the roof and we have found the skeleton of a horse, leafs, spiders...

Also, we have dived the Reinazo Surgence until an aerial zone where we need to unblock to continue.

Several months later, we have a lot of news. It was not possible to access to the electronic location equipment, so we tried to connect the cave with the outside through two Arvas (the skier’s equipment that they use to locate someone who is caught in the snow): four people in the cave and two people in the outside.  After digging and taking out around four tonnes of stones, we found a beautiful itinerary under the Picos de Europa.


1975 – (2:30), 10m pitch

1976 – 4 down Trumbio

1979 – SRT trip down Trumbio with Mike of OUCC. 3 small climbs, 10m pitch. (4:30) Trumbio entrance: 587m; final Sump: 482m; depth (barometric) 105m; depth (surveyed) 106m

2003testing LED lamps in real cave conditions

2012 – so overgrown we could not get to the cave!

2016 – successfully reached the entrance by circling to other side of the valley


Excellent introductory cave, down to the head of the pitch.

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 2022-11-25 by mfc.