Updated 30th August 1998; 19th February 1999; 17th September 2000; 7th October; 26th October 2001; 12th May, 7th June 2002; 8th November 2003; 14th May, 29th September 2006; 27th , 31st October 2007; 20th December 2008; 6th January 2011; 24th April 2016; 30th June, 21st September, 10th December 2018; 2nd September 2021; 8th January, 4th May 2022; 6th January, 8th February, 27th April, 8th May, 6th June, 18th September 2024

Note that the Matienzo caves Project survey needs amending as leg 13 - 14 across the traverse should be reversed to agree with the 2000 resurvey to the surface shafts. The GPS grid reference was taken summer 2001 and is at the left of the entrance looking in.
There is no description below of the passages found and surveyed by the Colectivo Piezo.

Valero Enrique y Soriano Ángel, 2007 has an area map showing the following sites: Rio Seco, Cueva Brazada, Torca de Blas, Cueva de La Pila, Cueva de Coquisera and Cueva del Coverón. The same publication has the length of the cave as 2900m and depth 260m.

The entrance was found fenced-off in August 2021. Also noted was a tube (not shown on the survey) at the northern edge of the entrance and, a few metres beyond, an undocumented cave (#5091).
For permanent rigging by the Colectivo Piezo see the note at the end of this description.

At the bottom of the pot, about 70m of passage runs in both directions, mostly below the main passage. As the roof of the lower passage is boulders, it looks as if it is only these which separate the two routes. Towards the entrance, the passage slopes up after a 3m climb down, and ends at a crawl and choke. In the opposite direction the passage ends at a boulder choke.

A walk round the left (handline rigged, August 2018) or right of the pot leads to an alcove on the right with charcoal and some pottery. The first lake is meet shortly after this with a inlet passage high on the right hand wall which should be bolted to. Further in, a ledge on the left provides access to a high level gallery, Galeria de las 400 Pesetas, running off on the right. One hundred metres along this route, on the left, three shafts enter from the surface, 40m above. (See anon., 2000e. The AEC Lobetum have surveyed and drawn out the 7 shafts that connect with Coquisera). The gallery reduces in size until a 90m shaft is reached. At the base is a narrow streamway. An awkward traverse over the pitch leads to a continuation of the passage and "further 95m pitches", explored in 1988. The re-exploration of this area, started in Easter 1994 and continued in the summer, discovered a major extension after traversing over the main shaft to a second pit.

Thirty five metres down the shaft, on the north side, a large passage can be swung into. The 6 x 5m stomp chokes after some 80m. A passage to east can be traversed into which chokes after 10m. Directly opposite the northern passage is the large entry to the southern passage which can be gained by a traverse. This large passage chokes after 230m after passing through a 30m wide chamber. This level, at an altitude of about 440m, appears to come close to the surface at the head of the massive valley which runs south behind Coquisera. A weak molephone link was achieved between the passage above and the surface.

Back in the vadose canyon, the floor slopes down to a 25m pitch, Sima de las Chinas which lands in another large level.

Heading north, "upstream", a calcite slope leads to the base of a chimney which is free-climbed. A rift heads back towards the Chinas shaft and ends at a boulder choke. Continuing upstream, a short may-pole pitch goes to another short pitch down, and a calcite choke. This lies below the entrance passage, and is probably related to the segment of passage below the 5m pot.

At the base of Sima de las Chinas a large amount of bones are mainly of deer. The main passage slopes down over boulders and slippery calcite. A side passage on the left contains a few bones - the remains of a bear; in 1964, S.E.S.S. reported this as the complete skeleton of a young Ursus speleus. This passage ends at a small aven on the left and a hole connecting with the main passage.

The main route continues through a strongly draughting crawl, shortly after which it turns sharp right. On the left at this corner there is a climb with two small chambers and a may-pole climb on the right to about 20m of unsurveyed passage. Traversing over the first climb leads to the awkward Popcorn Climb, the start of Quality Time. Sixty metres of passage and a crawl lead to a 5m free-climb down into a large chamber. A rift passage in the roof over this climb has been may-poled into, but didn't go very far. On the right of the chamber, a large aven is very near the second 95m shaft in the Galeria de las 400 Pesetas, but has no voice connection. Opposite the climb down, another climb up goes into a chamber with two sections of old passage going roughly north and south.
   In December 2023, the "Colectivo Piezo" group apparently explored beyond this area but without surveying the finds. Some details are in the 2023 Christmas / New Year logbook and elevation sketches have been shared. (See below)

Returning to the main passage, this continues to trend downhill, and an inlet on the left is too small to be followed very far. The passage develops into a wide bedding and opens out in a large chamber with a rubble slope at the angle of rest. On the right a side passage leads to two avens with possible passage at the top. Bolting started here in 1998. At the base of the rubble slope the stream is met, supposedly coming from the passage at the base of the 90m shaft. This can only be followed for about 30m through smaller passage, ending at a chamber with a couple of uninspiring digs.

Just before Sima de las Chinas a passage can be seen high on the right hand wall. This hasn't been entered but it seems to be heading towards the Galeria de los 400 Pesetas. On the left hand wall, just before the same pitch is a "passage" which proved to be an alcove after bolting. (Pictures 1  2).

The Sima de las Chinas can be traversed along the left hand wall, ending in a 7m pitch to the passage floor. Straight ahead, a boulder slope leads up to a large passage ending abruptly at a boulder run-in up to the roof. The survey shows this to be directly below Galeria de las 400 Pesetas. On the left at the end of the traverse there is a loop, which re-enters the passage at the top of the boulder slope. Several side passages off the loop all choke; one ends within 10m of the northern passage in the 1994 extension. A rift crosses over in the roof of the loop. It is blocked by a boulder but can be seen to continue.

Much potential remains such as a possible link with Cueva del Coverón (002).

A bolt climb in the entrance, to reach a suspected passage, yielded 10m to a sandy choke.

Ortiz (AM) lists two crustaceans: Stenasellus cf. virei Dollfus and Pseudoniphargus africanus Chevreux, while Pinto (AF) includes Cantabroniscus sanmigueliensis among the fauna. The bats Rhinolophus ferrumequinum and Barbastella barbastellus are recorded by Meijide (AY).

Pinto found Iron Age pottery in the area before the first lake in 1978, part of a Brazada-type urn. In 1981 a copper arrowhead, dated in the Bronze Age, was found at the top of the climb starting the 400 Pesetas Gallery. A fibula or omega-shaped buckle (dated to the 1st century BC) and a bone needle have also been found. A page of photographs showing some of the archaeological remains can be seen here. This area contained many broken and burnt bones, charcoal and pieces of pottery of the Brazada type and assigned to the Iron Age.
Because of it's north-facing entrance and the damp and cold vestibule, Coquisera is unlikely to have been used as a habitat for any length of time (Ruiz Cobo Jesús et al, 2008, p210).

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

Shaft entry
The surface pitch is marked 78 with an orange cow tag. Go between two upright rocks and use the natural belays (10m rope needed in total). First pitch is 28m to a slope of 4m to a second pitch of 26m. One rope will do as there is little rub. Follow the slope down to a flat-floored rift and "crab" through 4m to 400 Pesetas Gallery.

   In April 2016, farmers Ismael and Ciano were keeping a small herd of goats in the cave. One became marooned on a high ledge on the eastern wall above the first pit - a slip would have produced a fall of about 12m. An ascending route starting further into the cave ended above but just short of the goat's positon. A bolt and combined tactics allowed a rope to be tied around the animal's horns and she was hauled up then escorted out of the cave. (Photos)