Updated 14th October 2010; 25th April 2012; 17th September 2017; 7th January, 5th May, 22nd September 2018; 13th May 2019
The entrance is in a large depression just off the field in the woods at the far end of the Mushroom Field. A 5m climb down leads to a 5m crawl to a draughting rift of 15cm. The way on down was documented as open in 1986 and remained that way for 24 years.
The 2010 logbook account states that, by going to the left, it is possible to descend the slot (beyond previous limit?) and a further slot leads to a small chamber with a small, choked pit in the floor. The way on appeared to be a small rift below the first slot which was draughting strongly. This was excavated as an "extremely awkward" squeeze to a short section of rift passage followed by a "head first dive" into a squeeze to emerge below an aven. At this point a draughting boulder choke blocks progress. It would appear that the route on is down a rift which is blocked by boulders knocked from above. There is still a good draught and the site needs more work. There are loose boulders throughout the cave.
At Easter 2012, the site was smoke tested where "smoke only came back out of the open hole and not out of anywhere else".
Extensive work was carried out in the hole over the summer 2017 expedition: enlarging, stabilizing, surveying and photographing. The surveys below have not been drawn up as further work may extend the cave - or even link into the Four Valleys System. The site appears to be about 110m and at the same altitude as the western arm of Trident Passages in Cueva Hoyuca and also some 40m above the smoke test site in Drain Tester, Cueva Carcavuezo.
Work continued over Christmas 2017 / New Year when the entrance climb down was stabilised and a bolt left in a surface boulder for a handline down - useful also for lowering bags. In the low crawl at the base of the shaft, the floor boulders were removed and taken to surface, walls were capped out to a more comfortable size, leading to the low arch into the draughting chamber with a pool in the floor. The arch needs enlarging to make it a more comfortable size but this was stopped by 3 days heavy rain making water run down the walls and a number of failed capping holes.
At the same time, a large specimen of the Quimper Snail, Elona quimperiana (Férussac, 1821), was seen halfway down the entrance shaft in. This snail is on the IUCN red list (Least Concern category) and been previously recorded in caves.
Further work continued at Easter, summer and Christmas 2018 and, at Easter 2019 it was declared a 4 or 5-person dig. There was also a strong outward draught on a cool day.
Site 603 draughts strongly both in and out depending on outside temperatures.
Reference: anon., 1986 (logbook); anon., 2010c (summer logbook); Corrin Juan, 2011; anon., 2012b (Easter logbook); anon., 2010c (summer logbook); anon., 2017c (summer logbook); anon., 2018b (Easter logbook); anon., 2018c (summer logbook); anon., 2018e (Christmas logbook); anon., 2019b (Easter logbook)
Entrance pictures : 2012 and 2017
Underground pictures: summer 2017
Video: Draught at the entrance (YouTube)
Detailed Survey : summer 2017 (temporary) : sketch from logbook, 2017
Line Survey :
On area survey :
Survex file : summer 2017 : on the Four Valleys centre line file