A rave in a Gwynedd mountain that sent shock-waves through the community over health and safety fears and disrespect to fallen miners may have set a new World Record.

On Thursday, 15 October Mercury Prize winner Roni Size performed a one-off set 1,375 feet beneath Eryri, in Cwmorthin slate mine in a bid to get the record for the world’s deepest underground rave.

Evidence has been sent off for world record verification.

Darren Edwards contacted us earlier this month to express his concerns and those of others in Blaenau Ffestiniog. 

“People are also unhappy because local men lost their lives in the quarry in the past,” Darren told the ‘Cambrian News’.

“If anything goes wrong, it could become a huge disaster, and the location is not ideal for rescue/emergency services to get there in a rush.

“Temperatures will also be very cold.

G-SHOCK and Roni Size perform world record deepest underground rave at Cwmorthin Mine in North Wales
G-SHOCK and Roni Size perform at world record deepest underground rave bid at Cwmorthin (Picture supplied)

“Common sense tells anyone who knows about quarries how unsafe they can become in an instant.

“This could put Blaenau Ffestiniog on the map for all the wrong reasons.”

Mine operator Go Below said they held "deep respect for the industrial heritage of Cwmorthin”, and “a dedicated pre-event reconnaissance trip was conducted to evaluate and mitigate any risks unique to this event”.

With safety preparations in place, a group of ballot-winners in helmets and harnesses descended through the mine for around two hours, crossing waterlogged passages and underground ravines before taking on scrambles, zip lines and abseils to descend 1,375 feet.

G-SHOCK watch company staged the event as a reward for the people with the deepest commitment to toughness and music as it launched its new Mudman.

The rave only appeared after the final descent, with the decks, sound, lighting and recording equipment carried in on people’s backs.

Before the event, the sound team measured the mine's impulse response using convolution reverb. During Size's set, vibration transducers sent elements of the music directly into the surrounding slate. Geophones and hydrophones then captured what travelled through the rock, water and mud, bringing Cwmorthin's acoustic and geological response back into the performance.

The result was a set shaped by the mountain and the mine itself, rather than simply played inside it - drum and bass moving through a signal chain made from stone, water, engineering and the crowd. The finished performance was prepared for G-SHOCK Radio, with the full set soon available on Mixcloud.

Size said:  "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? It's the most underground of underground raves ever."

Before Size took over the decks, the team played ‘Hen Wlad Fy Nhadau’ through the underground sound system. The Welsh national anthem filled the deep chamber as the group gathered beneath the mountain.

The event also gave the group the first chance to get their hands on the new GDG-B100 MUDMAN watch ahead of its wider release.