Roni Size sets record with deepest underground rave in Gwynedd
Roni Size performed 1,375 ft beneath Eryri, sparking safety concerns and aiming for a world record as G‑Shock launches its Mudman watch.
Roni Size delivered a one‑off set 1,375 feet beneath the peaks of Eryri on Thursday 15 October, in a bid to claim the world record for the deepest underground rave.
The performance took place inside Cwmorthin slate mine, near Blaenau Ffestiniog, and was staged as part of G‑Shock’s launch of its new Mudman watch.
Organisers have sent evidence of the event to the relevant authorities for official record verification, citing the depth and the unique acoustic conditions as key criteria.
Local resident Darren Edwards voiced strong reservations earlier this month, warning that the rave could stir painful memories of the quarry’s tragic past.
“People are also unhappy because local men lost their lives in the quarry in the past,” Edwards told the Cambrian News.
Edwards added that “common sense tells anyone who knows about quarries how unsafe they can become in an instant,” and cautioned that the event might put Blaenau Ffestiniog “on the map for all the wrong reasons”.
Mine operator Go Below responded that the company holds “deep respect for the industrial heritage of Cwmorthin” and that a “dedicated pre‑event reconnaissance trip was conducted to evaluate and mitigate any risks unique to this event”.
A group of ballot‑winners, equipped with helmets and harnesses, descended through the mine for around two hours, navigating water‑logged passages, underground ravines, scrambles, zip lines and abseils before reaching the 1,375‑foot depth.
Safety crews were stationed at key points, and emergency protocols were rehearsed in advance to ensure rapid response should any incident arise.
The sound team measured the mine’s impulse response using convolution reverb before the set, then fitted vibration transducers to send elements of the music directly into the surrounding slate.
Geophones and hydrophones captured the vibrations as they travelled through rock, water and mud, feeding the acoustic data back into the live mix, creating a performance shaped by the mountain itself.
During the set, drum‑and‑bass rhythms reverberated through stone and water, producing a soundscape that blended the crowd’s energy with the geological environment.
“By the time we’re 1,375 feet underground, everyone there will already have shared an adventure.” And how much more could you reflect the environment than by pumping a set into the mountain, hearing the sound travelling through the slate, rock and mud, and bringing it back into the mix?
Before the music began, the team played the Welsh national anthem, “Hen Wlad Fy Nhadau”, through the underground sound system, allowing the anthem to echo through the deep chamber as participants gathered.
Attendees also received early access to the GDG‑B100 Mudman watch, a limited edition timepiece designed to endure the harsh conditions of the mine.
While the event has been hailed by some as a groundbreaking fusion of music and geology, others in the community remain uneasy about the potential hazards and the symbolism of hosting a party in a site linked to historic mining fatalities.
The organisers have confirmed that the full set will be uploaded to G‑Shock Radio and made available on Mixcloud, offering a chance for a wider audience to experience the unique acoustic experiment.
As the verification process proceeds, the event stands poised to enter the record books, potentially cementing Cwmorthin slate mine as the deepest venue ever used for a live electronic music performance.