Exploring Cwmorthin Mine – The Slaughterhouse
Whilst walking in the Moelwyns above Tanygrisiau the other week Morgan and I came across a whole load of mine entrances that led to caverns and passages that looked ripe for exploring. Not knowing much about them and not having the right equipment with us we resisted the temptation to enter them, but did look them up when we got home. The mines we saw were the Croesor and Rhosydd mines, but after reading a very good article about the Croesor-Rhosydd through trip I was glad we didn’t enter them.
“The Croesor-Rhosydd through trip is particularly dangerous and requires specialist equipment and the skill to use it correctly. A mistake or poor judgement in such an environment could easily cost you your life. Please don’t enter any mine unless suitably experienced, equipped and in the company of other competent
Whilst looking up info about the mines in the area and access to them we did however come across a geocaching event called Mae’r llad-dy, which translates into ‘The Slaughterhouse’ run by the Celestial Bar in the Dark Team. The event was a trip down nearby Cwmorthin Mine that we had passed on our way back down from the hills that day. Cwmorthin Mine is huge slate mine, the largest in the UK with a vast array of features including huge chambers, suspension bridges, plenty of mining history, equipment left in situ and some mineral decoration. The mine exists on many levels with a great many chambers on each level. Interconnecting passages join some chambers both from the rear and from above creating a warren of tunnels. Access to these mines is via gated entrances that are locked but anyone can get the keycodes if they want them. Exploring these mines isn’t such an undertaking as the Croesor-Rhosydd through trip, but still not something recommended without knowledgeable guidance.
The geocaching event was led by people who know the mines well and it sounded like an excellent opportunity to explore them ourselves. So, on Saturday Morgan and I made an early start and drove up to Tanygrisiau where we met lots of geocachers in a car park. We donned our hard hats and suitable clothing, signed our names on a piece of paper and then walked up the slopes towards the mine entrance. There were quite a few of us, too many really, and as is often the case with such things, quite a few people who probably weren’t really up to the trip. We were likely to be underground all day and there could be some slightly strenuous activities involved – not everyone in the world is ready for such things.
Morgan and I were of course more than ready, and we were soon scrambling our way down a steep incline, known as the Black Vein Incline, taking us hundreds of feet below the mountain. There were only few ‘guides’ so not really enough for such a large group of inexperienced people and the going was slow as we waited for those less confident and less capable in such conditions. This meant that there was quite a bit of waiting around, but it gave Morgan and I plenty of time to chat and look around.
We had a chance to abseil down part of the descent. Morgan and I were going to, but it was all a little haphazard so Morgan decided against it at the last minute and we continued our way down the incline, passing fallen mining wagons as we went.
At the bottom we climbed onto a thin scaffolding pole and clung to a chain for a pole walk over deep water before wading off along various tunnels and passageways.
We then climbed another incline and explored some more caverns before crawling through a tight gap in a wall only to emerge into another cavern with a narrow ledge to balance across above a perilous drop. This proved to go nowhere so those of us at the front who had done this back-tracked and met the others who were descending the incline towards a large cavern where we stopped for lunch.
After lunch there was a little more pfaffing about before we retraced our steps, up one incline, down another through some flooded passageways and off towards the pole-walk again. There were plenty of stops along the way to wait for people, to allow some to abseil and to find our way as the guides seemed to have disappeared for quite a while. There were a couple of other small groups of people exploring the mines today as well and it certainly looks as though there would be miles and miles of passageways and chambers to investigate. Maybe with a smaller group we could have seen a little more as there were passageways in every direction and plenty of exciting looking rope-crossings, steps and precarious looking bridges.
Eventually after 6 hours underground we emerged back into daylight. It was grey and drizzly outside, not the bright sunshine we had expected, so we hadn’t missed much in the way of summer – being underground on a day like today was fine and certainly something different. As usual Morgan and I had kept ourselves to ourselves whilst down there – we aren’t the most sociable when at such events, but we did chat to one lady who’s geocaching name was ‘FfiLli’. She seemed really nice and had plenty in common with us. Not only geocaching and exploring mines but beekeeping too.
All in all an exciting day in Cwmorthin Mines, and certainly a different way to spend a Saturday. We were even given a Mars Bar for the trip by the organisers – Now their group name ‘Celestial Bar in the Dark’ made sense!