Updated 19th February 1999; 16th September , 31st December 2000; 3rd Feb, 7th, 27th October, 16th November 2001; 3rd, 8th, 15th June 2002; 18th January, 8th, 26th November 2003; 6th November 2005; 27th October 2007; 29th September, 20th December 2008; 16th May, 18th November 2009; 16th May, 10th November 2015; 23rd March, 14th October, 3rd December 2016; 8th January 2020; 4th September 2022; 29th November 2023

   The cave was due to be gated early in 2001 and the steelwork was finally installed in December 2002. The gated entrance was vandalised in 2009 when part of the enclosing wall was knocked down. A trip to check on any internal damage also provided some photos. The cave is basically one large passage with plenty of calcite formations. It ends at a calcite slope that meets the roof.

   The Acanto web site (by the Federación de Asociaciones para la defensa del Patrimonio Cultural y Natural de Cantabria) has a section on Arte Rupestre esquemático-abstracto. Cofresnedo is one site with some detail about the black marks, along with an interactive survey.

   Cueva de Cofresnedo is one of the best archaeological cave sites in the "middle Asón" area and is the only one where some deposits can be ascribed with any certainty to the Lower Paleolithic. A cross section through an exterior excavation (from Ruiz Cobo Jesús et al, 2008, p188) can be seen here.

   The cave has the only Upper Palaeolithic remains of the Matienzo caves (Ruiz Cobo Jesús et al, 2008, p53, p72). Human remains (of 2 adults and 2 juveniles), pottery (742 fragments - minimum of 16 vessels), paintings and Iron Age artefacts have all been discovered. The cave contains some 40 schematic-abstract paintings. Smith Peter, 1998b shows the positions and has sketches of these markings. They are further discussed in Muñoz Emilio et al, 1995 and Ruiz Cobo Jesús and Smith Peter et al, 2001. There are also a number of animal remains and wall scratchings. The pottery discovered has been compared with that discovered in site 2139. (Smith P, Corrin J and Ruiz Cobo J, 2008). The same article dates the human remains to 3410±50 BP (c1700 BC) and 3000±60 BP (c1250 BC). (BP dates are radiocarbon dates; BC dates are date calibrated calendar years).

   Among the important objects which have been found are a copper arrowhead, an iron dagger and axe, a decorated copper plate, a high-tin-content bronze bead, a copper nail, a punic glass bead, a bone bead, a copper-alloy object with two holes and pottery of the Brasada (or Brazada) type, making this cave one of the most important Iron Age sites in the north of Spain.

   A Bronze Age bone punch (punzón) was excavated from the entrance chamber. (Drawing from Ruiz Cobo Jesús et al, 2008, p119). The volume also indicates that the cave, at that time, appears to have had dual use: as a burial site in the dark zone and as a habitat (not merely a refuge) in the daylight entrance chamber.

   Small fragments of medieval pottery have also been found.

    In 1994, a calcited straw or reed basket was described. This is near the end of the cave and is well trodden and half destroyed. Pablo Perez Vidiella took 3D photographs in the area of the basket in October 2015. (photo below). A 3d photogrammetry pdf of the results can be viewed. (It requires Adobe Acrobat Reader DC to view it). Just beyond the basket, possible ancient barley was recognised in December 2003. It was reported in 2008 that the cereal grains had been dated to around the 1st century BC. It is feasible that the basket is of the same age. Agricultural implements in the nearby Cueva de Reyes were also found to be Iron Age.

   A mill stone is described as being similar to the one in Cueva de la Orilla Mijeo. (Ruiz Cobo Jesús et al, 2008, p138)

   As part of a major revision, a trial dig in the entrance by Spanish archaeologists (September 2000) has revealed an Upper Palaeolithic level with flints and animal bones. In the small alcove (G4) where the juvenile lower jaw was found, more teeth and bones have been found along with a couple of pieces of pottery. Human bone has been dated to around 3410BP - a factor in suggesting a Bronze Age burial . Ruiz Cobo Jesús and Smith Peter et al, 2001 details all the finds and discusses the possible sequence of occupation. Pottery found in 1963-4 and 1980-1 is found here. Flints from a Middle Palaeolithic level (Ruiz Cobo Jesús et al, 2008) are shown here and a set of flints from level 4.3 (Upper Palaeolithic) (Ruiz Cobo Jesús et al, 2008, p74) are found here.

   Further work during 2001 has disclosed many remains; these will be displayed on-line in due course.
Ortiz describes several Stenasellus cf. virei Dollfus and a male Lithobius sp.

   Morlote Jose M et al, 1995 describes Cofresnedo as one of the Iron Age sepulchral caves in the area.

   (Matienzo archaeology article). Photos of some of the archaeological finds can be seen here.
   In June 2002, C14 dates for Cofresnedo were revealed (pers comm 13/6/02). "The Paleolithic deposit is about 31,000 BP or Aurignacian, and that's OK. The Mesolithic shell midden on the wall in the entrance is truly Mesolithic, but the bones in the chamber with the iron dagger are Bronze Age! That one's going to need some explaining away."

   Ruiz Cobo Jesús and Smith Peter, 2003 has the results of the archaeological work carried out since 1996. This is a definitive work about the cave with many photos, line drawings and surveys. The book also puts the finds in the context of other caves and deposits in the area. Ruiz Cobo Jesús and Muñoz Fernández Emilio et al, 2009 compares "Orza" type pottery with other finds in the Asón region.

   In October 2016, as part of Laura Deeprose's PhD work, a section of a calcite layer was removed. Dates and climate data from this layer will possibly correlate with data from Cueva de las Perlas and shed light on the demise of the Neanderthals in the area.
Reference Smith P et al, 2015 has a summary of the archaeological work, radiocarbon and thermoluminesence dates carried out within 2004 - 2016.

   In the summer 2022, a laser 3D survey was carried out by a Spanish group.

A Spanish publication, De Luis Mariño Susana et al, 2023, documents 2 pieces of decorated Iron Age pottery found on the Belén ledge.

References: Fernández Gutiérrez et al, 1966 (survey and photo); Beardmore W and Lenartowitz S, 1972; Kendal Caving Club and Manchester University Speleological Society, 1975 (survey); Penil J et al, 1981; Smith P, 1981c (photo); Manchester University Speleological Society, 1982 (survey); Cox G, 1973; Mills L D J and Waltham A C, 1981 (survey); Smith P, 1981a; Corrin J S and Smith P, 1981; Corrin J, 1983c; Smith P and Muñoz E, 1985 (survey); anon., 1983b (logbook); material in file; Smith P, 1985 (survey and photo); Pinto A and Canales F, 1985 (survey); Smith P, 1983; Ortiz E, 1968; Muñoz E, 1988; Smith P, 1988; anon., 1993c (Easter logbook); anon., 1993b (logbook); anon., 1994b (logbook); Neill A, 1994; anon., 1995a (Easter logbook); anon., 1995c (logbook); Morlote Jose M et al, 1995; Muñoz Emilio et al, 1995; Smith Peter, 1998b (survey); Smith Peter, 1998a (photo); Fernández Ortega F, Valls Uriol and Maria del Carmen, 1998 (photo); Smith Peter and Ruiz Cobo Jesús, 1999; anon., 2000c (Summer logbook); anon., 2000d (Xmas logbook); Corrin Juan, 2001; anon., 2001c (Summer logbook); Ruiz Cobo Jesús and Smith Peter et al, 2001 (includes drawings, surveys and photos); Fernández Ibáñez Carmelo, 2001 (includes dagger drawing); Acanto web site; pers comm (email 13/6/02); anon., 2002b (summer logbook); anon., 2002d (Christmas logbook); Smith Peter, 2002; Corrin Juan, 2003a (photo); Corrin Juan, 2003b (photo); Ruiz Cobo Jesús and Smith Peter, 2003 (photos, line drawings and surveys); Corrin Juan, 2003c; González Luque Carlos, 2003; Castaños Ugarte Pedro Ma, 2003; anon., 2005b (Easter & summer); Corrin Juan, 2006a; Corrin Juan and Smith Peter, 2007; anon., 2008e (summer logbook); Smith P, Corrin J and Ruiz Cobo J, 2008; Ruiz Cobo Jesús et al, 2008 (drawings, photo and survey); Ruiz Cobo Jesús and Muñoz Fernández Emilio et al, 2009; Corrin Juan, 2013a; Ruiz Cobo J and Muñoz Fernández E, 2013; 2015b (Easter logbook); Smith P et al, 2015; Smith Peter, 2016; Smith Peter et al, 2016; De Luis Mariño Susana et al, 2023
Entrance picture : misc : photos from Easter 2015
Underground picture(s): Families outing : Graffiti : large passage at entrance : autumn 2009 : Photographing the basket, 2015
various: Excavated skull and scratches; gating the entrance, 2002; red wall markings; misc from 1983 : Laser 3D surveying Summer 2022
Video: from the Cueva Aspio project studying the basket near the end (YouTube, 2015)
Detailed Survey :

1965	known cave	low res	high res
1975	known cave	low res	high res
1975	on area map	low res	high res

Archaeological discoveries: various pictures and links
Line Survey :
On area survey :
Survex file : yes (Amended magnetic declination December 2013 to align with Eur79 grid and coordinates altered to fit ETRS89 datum, April 2014.)