HOME | caves alphabetical numerical | cave search | maps & photos | archaeology | contacts | history | flowers | conservation | science | spain & cantabria | surface views | travel & weather | other caving web sites | bibliography | Span-Eng caving dictionary | Google Group | expedition details | general links |
Matienzo Expedition Caving - background information
Updated May 2017

The main Matienzo Expeditions occur around Easter and from the last week of July to the middle of August. Visits occur at other times, e.g. October / November, Christmas/New Year, February and Whit week.
New cavers, experienced and novice, are welcome: fresh perspectives and enthusiasm often leads to new cave discoveries!
This page gives a flavour of what happens above and below the Matienzo area.

The Area
Permissions, Grants and Donations
Camping and Catering
Caving Organisation
Caving Areas
Cave marking
More information
Upcoming expeditions
Shortened Bibliography

The Area
The 26km2 enclosed depression of Matienzo has taken some 2 to 3 million years to form. The imperviously-floored valley is surrounded by limestone hills containing hundreds of kilometres of cave. Water resurges into the basin at a number of points and most of it leaves at the northern end.

A major Spanish expedition took place in the summer of 1964. British-led caving expeditions to Matienzo have been occuring up to 3 or 4 times a year since the late 60‘s and the amount of known cave passage has risen from some five or six km to hundreds (over 380km, June 2017, see a summary sheet). About five to eight kilometres of cave are found each year, although in 1989 over 15km was surveyed, in 2004 some 10.7km and in 2008 over 13km. Collaboration with Spanish caving groups often results in new cave exploration. An area map shows the major caves.

Permissions, Grants and Donations
Permission to cave is given by Spanish speleological authorities within both geographical (about 96km2) and time limits. (The permit area can be seen here.) We were refused permission to cave during 1990 because caving occurred outside our designated area in the previous year. Although we do not have official permission to cave beyond the current permit boundaries, Spanish groups in adjacent areas may allow exploration in systems that we have previously explored. If in doubt, consult with Phil or Juan. The permit runs for the full year.
One of the permit requirements is a report of the speleological activities over the year. For this reason and because the permit is given to the Matienzo Caves Project, all people contemplating a caving trip to the Matienzo area outside of the usual expedition periods should ensure they are included in the permit by contacting Phil Papard or Juan Corrin (see the Contacts page). Full documentation of any new exploration(s) is required, ie logbook account, passage description, photographs and, if appropriate, a survey.

Good relations are kept with the villagers, the caving authorities (including the Cantabrian Caving Federation), other Spanish caving groups and the Guardia. We have had the support of the Ghar Parau Foundation. The grants recently awarded can be seen here.

To supplement any award, the expedition asks for an annual donation from cavers over 25 of £3.50 a day to a limit of £35, i.e. a maximum payment for 10 days. Younger cavers (25 and under) are charged £2.50 a day to a limit of £25. Sterling donations are preferred. Donations in euros will depend on the exchange rate.
This covers all group equipment (ladders, rope, bolts, rescue equipment, GPS, etc), surveying and some publication and IT costs. As well as paying during an expedition, there is also the preferred facility to pay caving donations up-front. (Contact the expedition treasurer for details).
A proportion of the donations is paid to Pablo for the use of the restaurant as a survey / drawing up area. The cost of any approved group equipment bought by individuals will be reimbursed. (There is also a charge for camping - see below).

Camping and Catering
Tents can be erected on the field behind the bar. (Location map is a pdf with note attached.) Only the eastern half of the field should be used and, as it is used for grass crop, vehicles should only drive on when the ground is dry and hard. 'Domestic' refuse should be disposed of in the wheelie bins found on the roadside.

There is a toilet block in the middle of the campsite which has showers, wash basins and toilets: an outside tap is for drinking / cooking water and washing small items of personal gear and equipment. There may be a rota for giving the facilities a quick wipe over. This water has to be paid for and should not be wasted. Therefore group tackle (ropes, ladders, etc) must be washed in the river.

A room in the block acts as a tackle store and is used for charging electric cells. Pablo at the bar charges 4€ per adult per night for camping, up to a maximum of 80€ per stay. This will be collected by the expedition treasurer and paid to Pablo in a lump sum at the end.

Everyone looks after themselves for catering, although alternative food arrangements can be made when long trips are likely. The tackle store has a microwave and fridge with small freezer compartment. There are supermarkets on the way to the beach or at Ramales, the nearest large town where travellers cheques can be cashed or cash cards used. Many oldtimers find a cool box and ice packs (re-frozen in the deep freeze at the bar or in the tackle store) a necessity to keep meat and veg edible. The restaurant, at the edge of the campsite, opened in 1994, has altered some eating habits, as have the meals at Bar Tomas and other restaurants. There is often an expedition meal (or two!) at the height of the caving frenzy.

Pablo and Anna at the bar have been very amenable about supplying late butties, up to about midnight, but this depends on the supply of bread and cannot be relied upon. The bar opens at about 10-30am (depending on the previous night's activities) and will serve an English breakfast or egg butties, etc. Bread is delivered to the bar around 10-30am. People can buy straight from the van and pay for it individually. The Bar Panadería also provides food.

In recent years hostel accommodation has become available in the village, eg at Cubillas (opposite the Bar Panadería) and bed and breakfast is available at the Anjana near Ramales and Bar Tomás in Ogarrio. Accommodation is also available further afield, eg at Solórzano, Lierganes and La Cavada. (See the Travel, Accommodation and Weather page).

Caving Organisation
Many of the cavers who come to Matienzo are not here primarily for the sport - they are people fascinated by the potential of the area and who pit their speleological wits against the draughting holes, deep shafts and tight crawls which could lead to 'caverns measureless'.

Caving trips occur because a number of people see the need for them and they are one of the expedition objectives. There are not many organised 'tourist trips' - the best way to see the caves is to get involved in a series of working trips - pushing, surveying, photographing etc. Anyone can organise a trip and, apart from the specialised (e.g. diving) ventures, all trips should be open to everyone. Obviously, each team on a major push/survey will have at least one person who has been in the system before and might well be the 'system expert'. Because systems tend to be pushed over a number of years, it is better that as many people as possible get to know a cave, rather than just one team. British caving clubs count for little in Matienzo - we are the "Matienzo Caving Club"; everyone should feel part of a whole expedition and be prepared to cave with anyone of similar caving aptitude.

Trip Sheets can be used to aid the organisation of the various parties that are likely to set off each day. The initial details of cave, objectives, date and number of cavers required are filled in by the trip leader(s) and cavers can then sign up for whatever takes their fancy.

Every caving team pushing a new system is likely to explore new passage. Each group should survey the passages as they leave the system so that the survey can be computer-drawn later that evening, allowing the next team to concentrate on the best leads. Each team therefore has the responsibility of ensuring that the survey data is converted to co-ordinates the same day and a survey drawn over the computer centre-line print out as soon as possible. An account of the new explorations should be written in the log book immediately and a description of the passage(s) should also be recorded (written or, preferably, typed).

Generally, information about new passages and sites becomes public as soon as they are found, and shared amongst the expedition members (and eventually on the web site). Anyone can then decide if they want to become involved in the exploration: the person or group that makes the find may invite people onto the next trip or you can ask!. There are some very rare instances where this process may not happen. For example, cavers who found Torca La Vaca near the end of the Easter 2008 expedition were sailing from Santander the next day. Other cavers explored 1.7km in the following days but did not finish the system, deliberating leaving leads for the original finders to push in the summer. The location of this site was not made public until the summer explorations had started.

Surface prospecting and digging are also vital parts of the expedition but they need to be researched before hand and should be tied in to the expedition objectives. Maps, digital cameras and GPS should be taken into the field. (See Publications and Cave Marking below). The Matienzo Caves Project and a number of individuals have GPS equipment for positioning entrances. The GPS coordinates database of entrances can be uploaded into (at least) Garmin and Magellan units but you may need your serial or USB lead. (GPS units must be set to ETRS89 or WGS84 and UTM/UPS). Digital photos (through a card reader) and video can be downloaded into the expedition laptops and / or main computer for future web publication and/or presentations. There is also a digital map of the area maintained with positions of entrances and cave centre lines. It is perfectly feasible, time permitting, to enter cave centre line data, add extra entrances and print the composite map out for underground or surface activity the next day. The large paper maps have been phased out and print outs from the digital maps are now the norm. Many cave surveys are also on the Project's computers and can be printed out before heading underground. Printed surveys can be scanned.
Android tablets and phones are used (with the Orux Maps application and downloaded Matienzo maps) to aid cave finding and identification. See the Orux Maps page.

We are extremely fortunate in having the use of an area in the restaurant at Bar Germán which acts as the expedition base / headquarters / office. This houses computers, part of the Matienzo Caves Project library and survey drawing-up area. The restaurant should not be seen as a general extension to the bar as Spaniards (and English) are paying to dine out!

Some members of the expedition have a general responsibility for overseeing certain major aspects. However, individuals should still see themselves as being responsible for the tackle they‘ve used, writing up, survey drawing etc.

  • Phil Papard: Expeditions organiser, permissions (with Pete Smith), main expedition reports
  • Steve Martin: Expeditions tackle master
  • Susan Martin: Expeditions treasurer
  • Juan Corrin: General coordination of the Matienzo Caves Project (with Phil, Steve and Pete): IT systems, surface maps, computer/cave surveys, library, web site.
  • Pete Smith: Permissions, Spanish group liaison and archaeology

The above can advise on areas and/or caves to push as can (at the risk of leaving many people out) Peter Eagan and Lank Mills. Many members of the expedition have expertise in all matters speleological. A number have been around Matienzo for years and will give advice and bull shit! Contact emails are listed here.

Personal caving equipment is obviously the responsibility of each caver. Carbide is not now provided nor used. Cells and batteries can be charged in the tackle store on the camp site. Group equipment is the responsiblity of the team using it. If a system is detackled, the detackling group should normally clean the equipment removed at the river.

More often than not, digging is required to enter new cave. The expedition has a good supply of digging equipment but it must be noted that a number of caves around Matienzo are important as archaeological sites and that digging may disturb prehistoric levels. Pete Smith has carried out research, working with Spanish archaeologists, and has catalogued various artifacts and paintings, and authored and co-authored many papers and books about the archaeology around Matienzo and beyond. Please keep your eyes peeled, looking at the walls and floor in any site that may have been inhabited. Pottery is especially easy to miss and tread on. The most common prehistoric pottery is black or black and red when fired (Bronze Age, 2000BC - 500BC). The expedition does not have permission to disturb archaeological remains. Any discoveries found should be left in situ and reported to Juan, Phil or Peter who will inform the appropriate authorities.

Everyone should remember that cave formations and deposits are to be enjoyed by all. Hence, thought must be given to minimising damage to caves and the decorations when exploring. If possible, volunteer for any conservation or restoration activities that may be taking place.

Each individual on underground ventures is responsible for his / her own safety and should have a blanket, spare light, etc. Sensible caving procedures should be adopted, e.g. lifelines on most ladder pitches, remembering that rescue is likely to be a protracted and costly affair. Rescue call-out should be via the bar and to the Guardia. A number of the expedition are current or ex-CRO members and would organise (at least initial) rescue procedures. Except for the simplest of rescues, it is likely that Spanish rescue teams would provide the expertise and man-power. It should be noted that rescued individuals extracted from a weather-related incident would be asked to pay if no regard has been paid to the weather forecast.
Taking out BCRA Insurance, ActivCard or a similar scheme is vital for peace of mind and pocket.  People without caving insurance are not permitted to cave. Details of next of kin, insurance policy numbers, etc. are taken as you arrive on camp or at the bar.

Caving Areas
Within our 94km2 there are caves and shafts of all sizes. The major cave networks are the 4 Valleys System and the South Vega System. Current system lengths and depths are shown on the Summary Statistics page. We have collaborated with Catalan cavers in pushing Cueva Vallina near Arredondo to the south. Pushing these systems is a priority, as is finding new caves from the surface. The area does not have a great depth potential: the maximum is about 680m.

The area map shows the main caves, roads and rivers. The following thumbnail descriptions aim to give a general feel of the area.

The South Vega System (survey)
Azpilicueta (333) and Coteron (264) are the high level entrances which drop down to valley level and emerge at Reñada (48). Cueva-Cubio de la Reñada contains a river which resurges into the depression to flow across La Vega; some of this water could come from Hoyon (567). Potential lies to the south (with Cueva Vallina already hydrologically connected) and to the west. It has been postulated that the Tejuelo system, to the south of Arredondo, could link with Vallina / South Vega.

North Vega (survey)
Torcon de la Calleja Rebollo (Toad in the Hole - 258) is an expanding system which could go anywhere: northeast to link with Mostajo (71), north and west into the unknown or even south to link with Reñada. Mostajo (71) could go northwest to emerge in cave 415, or north into the unknown. The caves are mainly dry but have large quantities of mud in the lower sections.

The Cubija / North Vega System (Cubio-Morenuca-Regaton-Mostajo) is in a prime position for extension, and is still wide-open in places.

The area of Cobadal may also connect through Sumidero de Cobadal into the North Vega System. The resurging river of Fuente Aguanaz (713) (survey), 7km to the north is the current (dye-tested) resurgence for Cobadal water. Torca La Vaca is another stream and fossil cave which was found over Easter 2008 and is "still going". A 9 sq km area centred around Ideopuerta, may also feed into a possible Regaton, Cobadal, Fuente Aguanaz system.

The low-lying area of Hoznayo (part of the permit from 2014) has provided the Torca Cañaos-Riocueva System which still has some potential.

The Four Valleys System (survey)
Nearly all the water in the Matienzo depression leaves through Carcavuezo (81), passes through Cueva Llueva (114), with an entrance in Llueva Valley, and resurges in Los Boyonnes (117) in Secadura. The cave is fed from water in Cueva Hoyuca (Uzueka) (107) which in turn is fed by water in Cueva Riano (105). The caves of Hoyuca, Riano, Llueva and Carcavuezo have been joined to form the 4 Valleys System. Some estimates put the potential passage at more than 100km. The Five Valleys System is a real possibility with Cueva Torno at Fresnedo nearly linked. Cueva-Cubío del Llanío may also connect.

This area is approximately 10 km2 of high level karst with little horizontal development. There are more than 200 known shafts, by no means all explored. There is plenty of surface prospecting and underground exploration waiting to be done. If an integrated drainage system exists, the resurgence could be the one below Cobrantes (110). It seems more likely that local networks exist with water resurging at various points around the mountain, e.g. at Ogarrio, and into known systems, e.g. Llueva, Carcavuezo.

Publications and research
There are 351 references to various articles (Spanish and English) and log books; many of these are in boxes in the back room of the bar. If you are interested in a site:
 - look in the card index where all explorations and accounts are catalogued and then
 - read up the various references.
The books likely to be of most use for general reading are listed below in a short bibliography. (Full bibliography).
The log books since 1974 to the present have all been scanned and a database built up of all entries. The database can be searched in the Matienzo Office to show all log book pages relating to any site. This facility is available to any expedition member in the bar and to people on-line with password access. See Logbook Search. Complete logbooks can also be browsed from this page.

Maps are available for the whole of our area. Sections of the computer-generated maps can be printed out and accompany everyone who is surface prospecting. Plastic wallets are available for weather proofing. (see Cave Marking, below). Cave passage and known entrances are shown at any scale.

All sites details are kept in a card index, paper archive, computer database and web site descriptions.

A paper publication (Matienzo Underground) used to circulate, based on cave descriptions from the web site, and people added to it or amended it. Appendices ordered the caves by length, depth and altitude. There was also a paper list of the 'unexplored' sites, a list of digs, and sites of archaeological and biological interest. This was occasionally updated in a paper version.
Nowadays, an on-line version of the descriptions (pdf files) is regularly updated and can be downloaded. The appendices and other information can be generated using the Cave Search facility.

Matienzo: 50 Years of Speleology, a 320-page, full colour, dual language book (with DVD and geological map) was published in August 2010. Details can be found here. Copies are also available to consult / buy in Matienzo.

Cave Marking
It is very difficult to permanently mark sites without disfiguring the limestone! Before 1994 we used cow-tags which had painted and embossed numbers. However, there is now much less need to mark caves as personal GPS equipment (without the wobble) became useable in 2000 and now WAAS-enabled devices allow accuracy to 3 or 4m. The settings / datum should be UTM/UPS and ETRS89 or WGS84 to agree with the paper and digital map grids.


There are over 4500 documented sites in the area and the potential for finding new passage remains as high as ever. But please remember to record your finds (describe, photograph and survey) so that documentation is as complete as possible and exploration does not have to be repeated!
A summary of the expedition aims and expectations, mainly for new expedition members, can be found here. A laminated card summarising the expectations is distributed to new members when they arrive in Matienzo.

More information
Contacts for more information are listed here.

Upcoming expeditions
A spreadsheet is available for each major expedition to show when people are going to be in Matienzo. Feel free to add yourself to the sheet or email Phil Papard or Juan Corrin with the details. It helps with planning, eg expedition objectives, other people organising dates, when to set up the office in the restaurant and when to have the expedition meal, etc.


Shortened Bibliography (mainly in English)
Matienzo Underground - the occasionally updated book, based on the web site. This shows the current state of (written) knowledge about the caves around Matienzo. There are regularly updated Matienzo Underground pdf files that can be downloaded. Hard-copy articles have not been produced in recent years, rather feedback articles for the Spanish authorities. These and other recent reports, papers and presentations can be found here.

(A) Fernandez Gutierrez et al, 1966. La depresion cerrada de Matienzo, Cuadernos de Espeleologia vol 2. 107pp + surveys & photos. The account of the original Spanish explorations.
(C) Kendal Caving Club/Manchester University Speleological Society 1975. Report of the British Expedition to Matienzo. 64pp + surveys + photos. The account of the expedition which surveyed about 15km in 6 months.
(T2) Mills L.D.J., Waltham A.C., 1981. Geomorphology of the Matienzo Caves. BCRA Transactions Vol 8(2), pp 63 - 84. Some speleogenesis hypotheses.
(T3) Smith P., 1981. Prehistoric remains and engravings discovered by the British Speleological Expeditions to Matienzo. BCRA Transactions Vol 8(2), pp 85 - 86.
(Y) Smith P., 1983. Iron Age Finds in Matienzo. BCRA Transactions Vol 10(3), pp 145 - 164. More up-to-date archaeological data is found for each cave in the Matienzo Update.
(BO) Corrin J., 1992. Matienzo '91 in Caves & Caving No. 55 , Spring 1992, pp 11 - 13.
(BR) Corrin J., Quin A., 1992. Matienzo '92 in Caves & Caving No. 58 , Winter 1992, pp 2 - 6.
(BZ) Corrin J., 1994. Matienzo '93 in Caves & Caving No. 63 , Spring '94, pp 24 - 27.
(CS) Corrin J., 1994. Matienzo '94 in Caves & Caving No. 66 , Winter '94, pp 10 - 14.
Corrin J., 1995. Matienzo '95 in Caves & Caving No. 70 , Winter '95, pp 24 - 27.
Corrin J., 1997. Matienzo ('96) in Caves & Caving No. 75 , Spring ''97, pp 16- 18.
Corrin J., 1998. Matienzo 1997 in Caves & Caving No. 79 , Spring '98, pp 31- 32.
Corrin J., 1999. Matienzo ('98) in Caves & Caving No. 83 , Spring '99, pp 26- 30.
Corrin J., 2000. Matienzo '99 in Caves & Caving No. 87 , Spring/Summer 2000, pp 43- 46.
Corrin Juan, 2001. Matienzo 2000. In Caves and Caving 89, Winter 2000/2001 , pp 24 - 27.
Ruiz Cobo Jesús and Smith Peter et al, 2001. The Archaeology of the Matienzo Depression, North Spain . In BAR International Series 975 , 224 pages.
Corrin J., 2003a. Expedition Report: Matienzo, Spain 2001. In Speleology Issue 2, May 2003, pp 17 - 19.
Corrin J., 2003b. Expedition Report: Matienzo, Spain 2002. In Speleology Issue 3, Sept 2003, pp 14 - 17.
Corrin Juan, 2005. Expedition Report: Matienzo, Spain 2003. In Speleology Issue 5, December 2005 BCRA, pp 10 - 14.
Corrin Juan, 2006a. Expedition Report: Matienzo, Spain 2004. In Speleology Issue 6, April 2006 BCRA, pp 20 - 23.
Corrin Juan, 2006b. Expedition Report: Matienzo, Spain 2005. In Speleology Issue 7, August 2006 BCRA, pp 22 - 25.
Corrin Juan, 2007. Expedition Report: Matienzo, Spain 2006. In Speleology Issue 9, April 2007 BCRA, pp 16 - 21.
Corrin Juan, 2007a. Expedition Report: Matienzo, Spain 2007. In Speleology Issues 10/11, December 2007 BCRA, pp 18 -24.
Corrin Juan, 2008 Expedition Report: Matienzo 2008. In Speleology Issue 13, May 2009 BCRA, pp 18 - 23.
Corrin Juan, 2010. Expedition Report: Matienzo, Spain 2009. In Speleology Issue 16, December 2010 BCRA, pp 12 - 16.
Corrin Juan and Smith Peter (editors), 2010. Matienzo: 50 Years of Speleology, 50 años de espeleología. Matienzo Caves. 320 pages.
Corrin Juan, 2011. Expedition Report: Matienzo 2010. In Speleology Issue 17, March 2011 BCRA, pp 8 - 11.
Corrin Juan, 2013. Expedition Report: Matienzo 2012. In Speleology Issue 19, December 2013 BCRA, pp 9 - 12.

Expedition Reports: Matienzo 2011 and Matienzo 2013
are with the Editor of Speleology

The Caves & Caving / Speleology references outline the discoveries over recent years. A full bibliography is also available.

JSC May 2017