site 2691

2691: Giant Panda entrance
Riaño 30T 452527 4799815 (Datum: ETRS89. Accuracy code: G) Altitude 214m
Length included in the 4 Valleys System (site 0107)
Area position : Site entrance in context : Logbook search

Updated 12th October 2007; 17th April, 7th May, 4th June, 4th October 2008; 16th January, 22nd October, 16th December 2010; 18th February 2012; 19th September 2013; 23rd May 2014; 17th May 2015; 20th October 2016; 10th January 2017; 22nd May 2017; 9th May, 1st July 2018; 28th January, 18th September 2019; 20th, 27th September 2022; 25th September, 6th November 2023

   The "top, all weather entrance" to Cueva de la Hoyuca situated in a large, deep depression with a stream sink. This hole drops about 60m down a set of climbs into the Gorilla Walk, a few minutes before the Second River Inlet. SRT gear is required and 40m and 15m ropes as shown on the RIGGING GUIDE taken from the Easter 2014 logbook. The route has been surveyed down to a cairn of two blocks in the Gorilla Walk.

CAUTION: The climb down from the surface through a road drainage tube then through a crawl in a tube seems (hopefully!) stable now (October 2023). (The previous scaffolding at the head and down the shaft has been removed and replaced by a road drainage tube. (See summer and autumn 2023 entrance photos below). However, care is needed exiting the tube and on the climb down into the small chamber at the head of the first pitch, due to the close proximity of the loose roof and walls. Also it is still possible that debris from the pitch head can fall all of the way to the bottom of the pitches, so it is still recommended one at a time on the rope and keep well clear at the bottom.
There is a short rope through the tube at the bottom of the Giant Panda entrance climb, but the rope on the main pitch has been removed due to damage, however the hangers are all in-situ. (Simon Cornhill, 2/1/2019)
The entrance was used in the summer 2019 and on 16th August 2022 when the first through trip into Matienzo was undertaken, via Armageddon (in Hoyuca) and site 0252 - after removing boulders at Armageddon that blocked the way.

   After the entrance climb and crawl, a descent of 25m passing several easy rebelays and a deviation leads to the bottom of a large rift. The top half of the main drop in this rift can become wet in high water conditions, but the water falls behind a flake leaving the bottom half of the pitch dry. A short walk down slope at the bottom of the rift leads to the final vertical 5m pitch which gets very wet in high water conditions. Landing in a cobbled floored chamber, SRT kits are best removed here (and left here if not needed elsewhere in the system). A slope down from this small chamber leads to the previous tightest point, a horizontal squeeze under a substantial flake (see photos A1 & A2, summer 2010). This has now been removed (Easter 2014) and larger people can use the route. The squeeze emerges in the top of a rift where a 3m free climb down regains the floor. The squeeze remains dry in high water conditions and the stream is met part way down the climb here.

   The floor of the narrow meandering rift is now followed down 3 more small climbs before a series of 4 x 90 degree bends leads to an awkward straight section of taller narrow rift. This is initially passed at floor level to pass under a chock stone before immediately moving up to the higher level to avoid getting stuck head first down hill in the tightening rift. This tight section was also capped out in April 2014. Horizontal progress along the upper level of the rift reaches the final climb down from Windy Inlet into the water in the Gorilla Walk. The trip down to the Gorilla Walk takes around 30 minutes for a party of 2. The return journey has been known to take significantly longer for tired parties!

The cave appears on the Cueva Hoyuca and the Four Valleys System Hydrology diagram.

[On a trip down in wet weather at Easter 2008 there was a sizable stream sinking next to the entrance, but this water was not met in the cave until the last rope climb at the bottom of the pitches. The stream then conveniently sinks down another slot in the floor just before the first squeeze and is rejoined in the rift beyond. The final awkward rift involved lying flat out in the water, with a substantial amount of water entering the Gorilla Walk out of Windy Inlet. The entire inlet is dry in normal conditions. In such high water conditions the Gorilla Walk had plenty of airspace from here onwards downstream.
The return journey was entertaining as the water levels had risen noticeably. In the Gorilla Walk the airspace was lower but still around 50cm up to the climb into Windy Inlet. (Beyond here the upstream airspace in the Gorilla Walk looked much less.) The rift squeezes were wet but not too wet, but close to the pitches it was difficult to locate the climb up the rift to the squeeze due to the amount of water coming down the rift. Climbing up through and soon getting clear of the water lead to the awkward section above, which was still dry. Back at the bottom of the pitches, the first short rope climb in the full water flow was very wet, but the main pitch was dry at the bottom. However some of the water was met part way up, disappearing behind a flake before the base of the pitch, and the top half of the pitch was rather sporting. Arriving completely clean at the pitch head, the emerging team got completely muddied climbing up the last few metres to the surface.]

History of excavation, closure and re-opening:
A large depression and stream sink with much activity over Easter 2007, when molephoning established that a point a few metres up the SW bank from the deepst point was 7m (+/- 3m) above the highest point in the Windy Inlet Series in Cueva Hoyuca. Digging occurred in a number of places and it appeared that a breakthrough into the bouldery top of a 30m aven was imminent. The depression takes a substantial stream in wet weather; the floor of the hollow is a mixture of large boulders, clay, soil and leaf litter.
At the end of July 2007, the dig had collapsed. Some substantial shoring was required.
At Easter 2008, two days digging saw the route through established and cavers emerged from Windy Inlet. The site was shored up in a temporary fashion until more permanent arrangements could be made.
October 2008; December 2010; May 2013: The entrance has yet to be properly shored up.
Easter 2015: The entrance shoring is very poor and the hole has collapsed before the pitch. There is no entry at present. See video.
Summer 2016: Repairs and gardening took place, but boulders at the pitch head need propping up before the next descent. Pitch head bolts have been removed and rope dropped down the pitch.
December 2016: The small void at the top of the pitches is now incredibly unstable, there is a high probability that a tired/unwary/clumsy potholer could dislodge one of the many keystones and initiate a full collapse of the roof and/or suspended floor. Where there used to be a wriggle onto the first pitch head this is now larger, there is a large loose gritstone cobble you have to get under which seems to be a major keystone for the floor, which definitely doesn't want to be disturbed.
April 2017: THE ENTRANCE IS BLOCKED AND CANNOT BE USED.
May 2018: Work continues to stabilize the entrance. A tube was installed to the head of the pitch, bolts fitted and a rope fixed through the tube for a cowstail.
December 2018: Entrance climb found collapsed but scaffolding and planks have stabilised the climb down and the route is open.
August 2022: The top pitch needs permanent rigging.
September 2023: Entrance shoring replaced with a drainage tube and fixed ladder. The head of the pitch needs stabilising.