Caves of South Wales Dragon

Blaen Onneu Quarry Pot

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Blaen Onneu Quarry Pot is a linear cave with several short pitches located on Llangynidr mountain. The stream in the southern end of the cave has been dye tested to Ffynnon Gisfean some 4 miles away in the Clydach Gorge, this coupled with the strong draught in the southern section of the cave indicates that there could well be a significant cave system still to be found.
Length 426m
Altitude 496m
Grid Reference SO 15907 16192
The cave was first explored by the SWCC in 1948. In 1990 the Llanelly diggers discovered 60m of passage in the northern end of the cave. In 1991/92 the Llanelly diggers made a significant discovery of passage in the southern end of the cave, breaking through into a streamway below two pitches.
Blaen Onneu Quarry pot is located in a disused quarry located just off the Beaufort to Llangynidr road and the few feet of tarmac at the start of the disused track that leads up to it makes a good parking spot for a couple of cars. The track can be followed up to the quarry, where you will see the large entrance to Blaen Onneu Quarry Cave in the far wall. Above and to the right is the entrance to Blaen Onneu Quarry Cave 2. Blaen Onneu Quarry Pot is found in the floor to the right of the quarry
Central Northern Outcrop Google map showing the location of Blaen Onneu Quarry Pot and other caves in the area.
Location map - click marker to show entrance photo
No known access restrictions.
The entrance to Blaen Onneu Quarry Pot is in the floor of the quarry and swallows up much of the rubbish that is inevitably dumped here. The 3.6m entrance pitch can be rigged from an 8mm spit located in the adjacent quarry wall, and drops you between the boulders and down onto the top of a large pile of debris. The bottom of the pitch is a tall rift, now very much infilled with rock and rubbish that has found its way down the entrance and the rift extends to the north and the south. Heading north in the narrow rift passage an iron bar is found wedged in a crack on the approach to the top of a narrow 10m pitch. Three 8mm spits are located in the rock face above the pitch head and a second metal bar is located across the rift above the pitch head. The top of the pitch is quite cosy, but it opens out as you approach the bottom of the rift. The passage continues northwards with occasional climbs and crawls through breakdown to reach a small chamber with a choke at the end. To the left is a climb down into the passage below that almost doubles back on itself for a short distance. From the bottom of this passage you now enter the 1990 extensions discovered by the Llanelly Diggers, this is a section of tight crawls through breakdown to eventually enter a chamber. Here a passage leads off to the right, but closes down. The way on is a 2.2m pitch that drops you into a second chamber.
From the entrance pitch a descent down a loose boulder slope takes you into the southern section of the cave. At the bottom of the slope a squeeze through a restriction takes you into a small but clear passage, this continues until a junction is reached. Ahead the passage continues until it eventually closes down. Following the draught through the slot to the right you enter and unstable area dug through in 1991/2 by the Llanelly Diggers. The strong draught is followed to a point where the route is down through a vertical scaffolded section. From here a squeeze leads you to the approach to the top of Twin Peaks pitch. Care should be taken as you step across the first hole to approach a short rift passage that descends to a small ledge at the top of the main pitch. A scaffold bar at the start of this short rift section allows you to rig some protection as you approach the pitch. A ring and a plate hanger are located in the walls of the rift over the pitch, these are no doubt now nearly 20 years old so care should be taken. The pitch descends into a roomy chamber with two large ledges on the way down. As you descend you are aware of two large boulders perched precariously in the wall of this chamber. From the bottom of this chamber a passage leads off to the south, but closes down after about 30m. The way on is to take the tight crawl to the north which leads via a tight descent into a chamber of stacked rocks. The passage ahead can be followed for another 20m but closes down. The way on is to carefully climb down the scaffolded shaft this leads to a tight squeeze into an unpleasant and tight passage. This leads to the top of a 5m pitch that leads into a chamber to meet a small stream. This stream can be followed in a small passage for about 100m before becoming too tight.
Entrance Pitch 10m ladder plus long belay.
Northern Pitch 1 10m ladder plus belay.
Northern Pitch 2 3m ladder plus belay.
Southern Pitch 1 (Twin Peaks) 10m ladder plus belay.
Southern Pitch 2 5m ladder plus belay.
An SRT Topo rigging guide is available from the references below.
Cambrian Cave Registry for Blaen Onneu Quarry Pot
Adrian Fawcett's South Wales SRT Topo Guide Including Blaen Onneu Quarry Pot (PDF)
Adrian Fawcett's South Wales SRT Guide Home Page (MS Word)
Descent 106 Article p34-35 on Blaen Onneu Quarry Pot Southern Extensions | Ashley Dickenson
Descent 98 Article p26-27 on Blaen Onneu Quarry Pot Northern Extensions | Ashley Dickenson
Caves of South Wales | Tim Stratford | ISBN: 1-871890-03-9 | Published by Cordee
The Caves of the Central Northern Outcrop | Tony Oldham
There are no official fixed aid in this cave. Any anchors will be over 20 years old now. There are many loose rocks around the entrance in the quarry floor.
The photographs and information of this page has been provided to help cavers planning trips. Caving can be a dangerous activity, if you are interested in exploring caves please join a caving club so you can enjoy a safe introduction to this sport. Local caving clubs are listed on the links page or you can visit the 'New To Caving' website for more options.
If you feel that any of the information is incorrect or should be updated please contact us.