1800: Fridge Door Cave
Riaño 30T 451162 4800782 (Datum: ETRS89. Accuracy code: G) Altitude 118m
Length included in the 4 Valleys System Vertical range -17m + 20m
Area position : Resources : Logbook search

Updated 27th April 2012; 23rd November 2013; 23rd May, 2nd December 2014; 30th April, 19th October, 5th November 2016; 30th September 2017; 24th September 2018; 8th May, 14th September, 12th November 2022; 17th May, 21st September, 5th-8th November 2023

   Fridge Door Cave was joined to, and became the 16th entrance to the Four Valleys System (0107), when a dig in Cueva Llanío (3234) broke through on 5th April, 2023. The length of Fridge Door Cave before then was 1248m. With this extension and other finds at Easter 2023, the length of the Four Valleys System grew from just over 70km to 71666m. (The extra survey (23m) from Llanío ending at 3234-23-01.11 connected at station 1800-22-06.81 in FDC).
   There was further activity in this area in the summer 2023. The Boob Tube (5000) entrance to Fridge Door Cave was opened up on July 22nd to become the 17th entrance into the Four Valleys System. It is now the favoured entrance to Fridge Door Cave as it involves no diving and an easy route to the far north of the cave. Vaca Bypass (5368, opened up after a short dig) was also linked into Fridge Door Cave at the downstream end of sump 2. This is not a favoured entrance although there are still leads in Vaca Bypass to pursue. Vaca Bypass became the 18th entrance to the Four Valleys System.


   An excavated shaft top (enlarged in July 2018), just up from the track, is covered with a fridge door. The ladder is best rigged from the tree as this puts the ladder in the middle of the entrance. A previous GPS reading is VP5126(0)0098(8) Altitude 130m. The current position is the result of a surface survey.

   A 6m shaft descends to a pool. The pitch was re-explored during very dry weather in October 2013. On this occasion the cave was found to drop into a stream passage generally 3-4m in diameter with a small flow of water, leading after 130m to an upstream sump. The water level was lowered by 5cm in October 2014. A climb at the sump leads to tubes. The main passage contains deep mud, and is largely sumped in wetter conditions.
    Some draughting passages around the base of the pitch may warrant a further visit, one was connected to a climb from the streamway.
   The downstream end (near the entrance), should be the feeder to Cueva Espada.
   A dead goat prevented entry in April 2014. The body disintegrated, spilling out maggots and entrails when an attempt was made to remove it. It had disappeared 6 months later.
  At Easter 2016, when water levels were high, the site was investigated by Jim Lister (video):
- downstream - taking a lot of water, blocked by boulders.
- upstream - left hand side pool is blank after 2m.
- upstream - under the way in, dived for 7m (duck leading to dry passage in summer). The diver turned around as believed Bunnies and Beer passage sumped to the roof.

   Intensive diving work took place over July and August 2016. The upstream sump was dived and surveyed by Jim Lister past a couple of airbells to a chamber where an inlet trickles in and a possible route required capping. Colin Hayward subsequently inspected an underwater arch on the right near the end of the sump. At the moment this is too low over a large silt bank. The upstream passage seems to be heading away from Cueva Llanío and under the ridge. However, water may be coming in from Cueva Llanío or further afield, eg site 3451.
   On the single trip in August 2017, Jim Lister capped out the "possible route" constriction beyond the sump and continued upstream for 31m where another sump was met (sketch survey).
   Despite 2018 having a dry summer, the route upstream from the base of the ladder remained completely flooded, thwarting dives at the "usual" sump. (It may be possible to lower the downstream stream bed by digging at the back end (upstream) in Cueva Espada.


   A major breakthrough was made by Jim Lister in April 2022 when, over a couple of trips, 589m of passages were surveyed including a high level that headed back to the entrance and a draughting dig that corresponded to a dig in Cueva Llanío. The following account has been extracted from longer logbook entries made by Jim over his initial preparations, dives and passage exploration. Further information has been added from logbook accounts of two trips (13th and 15th August 2022) by Jim and Mark "Killer" Smith.

Preparation
   Silt screws have been placed at appropriate distances along the initial passage so that a guide line can be installed in case of flooding! (The passage floods to the roof and is 100 meters long approximately.) Digging out the line was required in sump 1 as it was buried in mud banks. Two eels were encountered in the sump although they could only be seen for a short time due to the silt causing very poor visibility.
    The dive base was reached and, taking my mask and reel, I headed towards sump 2. There is a slot and possible climb up into a continuation in the roof with a good echo above where, all those years ago, I capped my way into the continuation. I squeezed through the capped bit and climbed down 12 ft, to the bottom and looked for the way on which looked different to how I remember it, I tied off the dive line and ducked under several arches until there was no obvious way on except for below water, which was now out of depth and murky. The dive line was tied off to a good anchor point (eye hole) in the roof.

14th April 2022
   Dived sump 1, with survey kit and haul cord, survival bag etc. Transported kit to sump 2, not easy as it needs carrying up climb, taking through capped squeeze and down the free climb on the other side. I took one 300 bar seven litre cylinder through first and brought it back as a test as I was not sure if it could be done and did not want to get stuck beyond sump 1!
   Sump two dived, with the two 7 litre cylinders, no visibility most the time by feel. It seemed roomy and shallow, mud floor, with big soft silt banks, some arches, a few bends. A quarter of the way through I found a nice eye hole in the roof to tie the guide line to, which was reassuring! I placed 4 silt screws in, one of which is on a sharp right hand bend, hopefully it will not cause unaware divers a problem with their legs going under the line and their fins snagging? Another silt screw was placed and the diver passed under another arch before meeting a steeply ascending mud slope that lead to surface in a large chamber.
   Another silt screw was set into the steeply ascending mud slope and the guide line was tied off. The passage was extremely wide with a steep mud bank in front, with what appeared to be two passages leading off at the top, behind the diver behind the sump pool appeared to be a large alcove - possibly a big passage?
   The passage in front, on the left is 3m wide by 3m high, with a small dried up stream bed along the middle and firm mud banks sloping up along the sides. (Very simular to the passage leading from the entrance to sump 1.) This passage was followed till it was partially blocked by a boulder choke, with what appeared to be passage above?
    The choke was passed easily and the passage was followed until eventually a side passage on the left was encountered. This was followed to an aven with a 2m blind, pot below. Above the aven appears to be blind but a large slot looks very exciting with what looks like a chamber or large passage.
    Back at the main passage this continues to a sloping mud floor which falls away down to a long, low duck. This was passed in the summer. (Survey batch 22-04; stations 36 - 62) leading up a sandy slope to a T-junction. Left went back down into the streamway which led quickly to Sump 3. Right led up a sandy passage that led to a cross rift with a high roof. Right hand route followed to in reasonably wide passage over calcite boulder climbs before ending in a small chamber with way on in roof. Left continued with small stream and ended with a mud choke in the floor with the way on looking like a climb requiring equipment.
   At the dive base, the diver waded across the sump 2 pool and, after several attempts and the construction of an improvised foot loop made from spare dive line, was able to climb up from the water to the bottom of an ascending mud ramp. The steep ramp leveled out and the mud changed to clay and then to sand.
    At the top of the ramp, the passage was 4m with a arched roof, the floor was of crystallised sand that crunched under foot. The passage was followed to a junction, which had a two well proportioned passages leading off, and some stalagmites and to the left, giving the Junction its name. The cave here is different in nature and a lot higher than the passage previously explored, which is active stream way. Due to time constraints the diver made his way out.

18 April 2022 Up into Sandy Passage
    The diver installed a dive line along the dry passage between the entrance and dive base (200 meters) in case the passage flooded to the roof! which was likely due to the poor drainage at the Espada end and the potential for bad weather. Note: The passage is blocked beneath the entrance pitch and the water takes weeks to drain through the blockage / choke into Espada cave. This causes the passage between the entrance and sump 1 (Fridge Door Cave) to back up in heavy rain and stay flooded for weeks.
    The line was belayed to silt screws, which were sank into the deep clay banks, found on the passage sides, Much smaller 3 litre, 300 bar cylinders were used. Sump 1 was passed and the awkward climb up to the capped crawl and down the other side was completed. The visibility in sump 2 was zero so no attempt was made to survey it. The tags on the guide line were counted and confirmed sump two is only 55 meters long.
    The last survey point from the previous trip was the silt screw at the edge of the sump pool, 1800-22-02.27. This was used for the start of the Sandy Passage survey and nominated as station zero for batch 22-03. The steeply ascending passage was surveyed through the change to sand, continuing southeast to Stalagmite Junction.
    The left hand passage was explored first as it was thought most likely to be heading towards Llanío. The passage was surveyed as it was explored. A hole in the floor where a small stream sinks (impenetrable) was encountered and named the Bear Pit. It's only 1.5 meters deep and a few meters long and is best passed on the right hand side. Just passed the Bear Pit is a small inlet passage on the left (station 22-03.19) with a small amount of water running from it. A further 15m along the passage stalamites can be seen on the roof and a slight bank of calsite acts as platform for some stalagmites. Behind them a large passage can be partly seen, behind a rock arch with a shaft in front with steeply, well decorated sloping sides! The end of survey in this passage, station 1800-22-03.21. In August '22, the Jaws of the Shark pitch was traversed over and the next pit was explored and found to be blind.
    Returning to Stalagmite Junction, the survey and exploration continued! Turning right the passage / chamber drops down a 2m bank which the stalagmites are located on and then gently meanders right and then left. It then reduces in size to a passage of a few meters wide, before then opening up into a mud floored chamber with a steeply sloping floor - Mud Slope Chamber. Down slope, the chanber ends in a passage which descends down a very steep twisting passage, 2m by 3m dimensions. This was explored in the summer for about 25m, ending in a mud choke. (Batch 22-07)
    To the left the chamber continues up slope (smooth round roof with cracked mud/ clay floor). At the top, a passage called "Buttercup (Daisy?) and Stitch" is encountered. A big alcove is passed on the left, then well-proportioned unexplored passage is also passed on the left. (Station 1800-22-06.33 is the survey tie in point).
   Exploration from station 33 occurred in the summer, 2022 as an ascending branch which led to a chamber with some unusual whirlpool features and "stick men" symbols before ending in a chamber with two ways on – a flat out crawl dug by MS leading to a steeply descending tight crawl. The other route was above and was an ascending crawl with slabs which were dug by JL. Passageway got smaller but continues and could be easily dug. The MS route (station 22-06.82) seems to be a mere 4.8m away from a connection with Cueva Llanío (3234).
    The main passage then changes and becomes "vadose", a very comfortable 2.5m wide at the bottom which has a sandy flat floor. A chamber is reached with unexplored passages leading off on both sides, the left hand being " Vadose" and of simular proportions as the main passage (later connected through to Stairway to Heaven), the right hand side passage is a high thin slot that also warrants future investigation.
    A short distance along the main passage yet another chamber is met, this time with three passages leading off, two on the left and one on the right. A mud choked passage is then passed on the left (possible dig) and then a tight crawl on the right with some stalagmites on the roof.
    The cave then splits into three: the right hand passage becomes a wide, stooping size passage which was left because of the delicate stal on the roof; the left hand side goes up a slope and splits into two - the right hand side continues for 7m and rejoins the righthand passage with the stal mentioned earlier; the far left passage which is smaller 2 x 2m, with calcite floor.This continues steeply upwards, and is called Stairway to Heaven.
    Back at the previous junction, the main passage continues and a passage / passages on the left emit a draft (station 22-03.62, is the tie in point here). This is now the best place to continue in this direction - the altitude is the same as the car park infront of the the farmhouse) as the continuing "main passage" eventually ends in a large, mud / clay run-in choke (altitude 122m, 15m below the surface)
    Going back to Stairway to Heaven passage, this continues to a junction. A narrow, twisting passage here ends after a few metres in a round chamber with no way off. A route to the north leads back down to Ariadne Passage.
   Stairway to Heaven eventually becomes a scramble up brown calcite to a wide low slot, with a few short dumpy stalagmites in it. In the summer '22, this was easily passed into a large chamber with a good echo. Roots and surface insects were noted in this chamber. At the top of the chamber, left led to a low passageway where a tree root was spotted (near station 22-06.93). Right led to a large walking sized passageway. Upon noticing the floor moving it was realized this passageway was the top of a rift heading down some distance. There were a few holes in the floor but a rope and bolting kit would be needed for descent.
   Station 22-06.93 was fixed by sub-phone (15/8/2022) and found be (after consulting the satellite photo) at 30T 0451310 4800848 - some 35m away from the original position, but only a couple of metres from the surface. A likely second entrance dig site is a few metres downhill, under a limestone roof. One exploratory drill down in the autumn 2022 found about a metre depth of soil. (The centre line 3d file shows station 93 a couple of metres distant, a consequence of trying to lose the significant survey error in the unsurveyed Sump 2.) See "Summer and autumn 2023" below.

    Note: Correction fluid used to mark stations and waterproof paper tags.

Work at Easter 2023 (See survey 1800-2023e-01.pdf)
   The cave was connected to Cueva Llanío on 5th April (when station 81 was seen) then further enlarged to allow a full team through into Fridge Door the following day. A team also visited on the 8th.
(i) The route beyond Jaws of the Shark was rigged with a traverse line. A climb down (p5) entered a small, excavated passage that could be pushed with a hammer. The end, up a slope at station 23-01.4 is close to station 3234-10-11.27 in Llanío. The latter lies 18m above and 13m horizontally away from 01.4 at a bearing of 135°.
(ii) A line was installed down the slope and across sump 2 making the crossing to the northern passages rather easier.
(iii) The large void was noted before the duck to the north of the sump 2 pool. There was some doubt as to the location of the void - in the choke or where marked on the survey at station 22-02.0.
(iv) Many photos were taken on both the 6th and 8th when most passages were visited.
(v) A pitch dropped at the end of Ariadne was dropped but became too small.
(vi) Other possibilities for digging out to the surface noted in the southern-most passage, running parallel to, and just under, the hillside. This was extended to depth in the autumn 2023, see description (v) below.

Work in the summer and autumn 2023 (See survey below)
   After a relatively small amount of digging close to station 22-06.93, which had been previously sub-phoned, a hole was made big enough for cavers to exit. The new entrance, Boob Tube (5000), was later provided with a short length of drainage tube (foamed, pinned and cemented in place), push-off steps in the roof at the bottom of the tube and a lid to keep animals out. See 5000 for more details.
(i) Vaca Bypass (5368) was opened up and connected just downstream of the sump 2 dive line. See 5368 for more details.
(ii) The new Boob Tube entrance was used for all of the exploration carried out after 22nd July. To the north, before sump 3, a climb up at station 22-02.0 enters high level passages heading back towards sump 2 and a draughting route northeast through Stone Eye Passage (batch 23-02), down a p6 (to the downstream end of sump 3) and a rope-protected climb up to the easterly continuation. The route continues through Matienzo Hash House Harriers, where a sloping inlet rises to the south from station 23-03.6 (batch 23-05), then into the bouldery Diamonds in the Sky where stal are seen 20m up. In this chamber, a slope down to the north meets a small passage with a small stream which sumps up and down stream.
    Continuing east (On On), a handline is required in a rift and water enters from an aven. A hands-and-knees crawl continues above the rift and leads to a complex chamber (around 23-3.27) with several ways on. A climb back up to the west enters On On (Upper level) that ends at a climb down (requires tackle) into Diamonds in the Sky. When explored in October 2023 it was thought that a roped climb up into the upper level would be an easier route than On On.
    Part way along this upper level (at station 23-07.8), a small route sets off to the north, then east, becoming progressively larger as a sandy-floored tube. The Crown Prince of Denmark's New Clothes has a number of unpushed side passages and exploration has currently stopped at a sloping chamber with a tall mud run-in. The route continues on the other side.
    The straightahead route from the complex chamber is draughting and has a few helictites. (batch 23-03) The draughting route continues east and south, up a roped 3.5m climb, and continues to station 23-04.16, beyond a a crawl under possibly loose boulders to a probably blind p6. A bolt has been put on each side of the pitch for a line but the calcite bridge on the side seems stable enough. Stal in the Stal Garden, were smashed to gain entry to a strongly draughting low passage. This is batch 23-08, Low in Knickers and it has several flat out crawls with a number of side passages. This route was first entered in the autumn 2023, but not pushed to any conclusions. The summer '23 exploration at the north end of FDC added 491m to the length; the autumn visits another 291m. (A blog account by Peter Eagan of the extensions can be read on pages 8 and 9 of the autumn logbook or here (date is 29/10/2023)
(iii) The Vaca Bypass entrance added 408m to the system. See site 5368 for details.
(iv) Sump 3 was dived by Jim Lister, emerging at the base of window to the east of the new p6. (Not shown on survey.) There could be others possibilities in the sump.
(v) The passage running west from the Boob Tube entrance was extended in October 2023. Starting at station 23-09.16, a small hole and crawl heads back east into the top of rift 1. A p6 on ladder leads to a crawl into rift 2. It is possible to get along the top of rift 2 secured with rope from 2 bolts. The rift gets narrow, but crawl size at the top and may be passable by removing a couple of loose boulders. Iy is possible to see 12m along. This was not pushed. The second p6 leads from 2 bolts to the bottom of rift 2, where the third p6 through a tube leads to the bottom. All passages seem to end in Ø 20cm holes with some mud. We were there on a non draughting day, and there was not a clear draught. Surveyed for 59m; batch 23-09. [Torben Redder]

Note on the survey alterations after summer 2023
Now having 3 entrances in quite accurate, known positions - and 5368 joining in at a known point in FDC - the Survex survey has been calculated using just the above-water data. The data is then fixed by *SOLVE before the dive data is used. The ends of the sumps 1 and 2 (and 3) have coordinates plotted directly from the above-water data rather than using the previous sump surveys. There are substantial differences between the old 2023 Easter Survex and drawn surveys and the summer 2023 Survex and drawn surveys - hopefully now nearer the true positions.

Link to entry in the Cave Diving Sump Index.

References: anon., 2002b (summer logbook); Corrin Juan, 2003b; anon., 2012b (Easter logbook); anon., 2013e (autumn logbook); anon., 2014b (Easter logbook); anon., 2014d (autumn logbook); anon., 2016b (Easter logbook); anon., 2016c (summer logbook); anon., 2017c (summer logbook); anon., 2018c (summer logbook); anon., 2022b (Easter logbook); anon., 2022c (summer logbook); anon., 2023b (Easter logbook); anon., 2023c (summer logbook); anon., 2023d (autumn logbook)
Entrance pictures: 2002, 2013, 2022 : Sub-phone location (#5000), August 2022
Underground picture(s): 2016 : 2017 : April 2023 (Peter Eagan) : April 2023 (Torben Redder) see 3234 : Summer 2023: Stone Eye Passage and Matienzo Hash House Harriers : autumn 2023, batches 23-07, -08, -09
Videos: investigating pools, Easter 2016 : sheep disposal (YouTube) : sump diving videos summer 2016 (YouTube) : 360 ° surface subphone August 2022 (in hand) :
Underground explorations and possible second entrance, August 2022 (YouTube) : Stone Eye Passage and p6 area, summer 2023 (YouTube) : Explorations around batch 23-05, sump 4 and station 23-04.16, summer 2023 (YouTube)
autumn 2023 explorations (YouTube)
Explorations at Easter 2022 by Jim Lister - all videos on YouTube
1 Down entrance mudbank to sump 1 (5:07)
2 Traversing the awkward passage between sumps 1 and 2 (12:06)
3 New: Mud choke back to sump 2 (11:16)
4 New: End of passage heading toward Llanío (5:37)
5 Dive out through sump 2 (7:47)
6 Going out through newly enlarged excavated section to base of ladder and exit. (4:26)

Detailed survey: sketch from logbook (2002) : survey (2013) : survey (2016) : additional sketch after summer 2017 : survey Easter 2022 : survey after summer 2022: after Easter 2023 : after summer 2023 : after autumn 2023
Line survey:
On area survey:
Survex file: with Espada, Llanío (Amended magnetic declination December 2013 to align with Eur79 grid and coordinates altered to fit ETRS89 datum, April 2014.) : Stand-alone after Easter 2023 : After Easter 2023, now part of the 4 Valleys System
After summer 2023: Stand-alone (with 5000 and 5368) : with 5000 and 5368 as part of the 4 Valleys System

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