14/10/2026
📆 in 1842 the sea level drainage tunnel, known as the Penmorfa Adit, was completed. It had been over eight years in construction, with a team of 12 miners working alternately day and night (except Sundays) to complete.
The tunnel had been dug by the miners working their way in a straight line from West Shore in the direction of the mines. In the final moments of the adit's construction holes were drilled at the end of the 800 metre long tunnel to release the water from the area underneath the mine workings. This water gushed forth at roughly 1,800 litres per minute!
The creation of the Penmorfa Adit allowed for deeper mining, extracting copper ore from below sea level on Great Orme. It was an engineering feat for the town, and so celebrated that an englynion (Welsh language poem) was written in honour of it. Old Mine (where our site is located) had a one third share in the tunnel and New Mine two thirds.
Today this adit continues to drain water from the mine, if you walk to where Abbey Place meets Abbey Road you'll see it's entrance, before the water is sent underneath the road, into West Shore Boating Pond and ultimately out to sea.
Former Great Orme copper miner Thomas Rowlands recalled seeing fellow miner Hugh Hughes working "in Penmorfa to grip the two handles of a wheelbarrow and to lift and turn it over his head, an achievement beyond the capabilities of any other Llandudno resident" [sic]. Anybody who has ever been inside the adit can only wonder how Hugh might have managed to do this!
Thanks to Don Smith who has shared with us these photos.
📸: Great Orme Mines manager Nick Jowett seated at the entrance to Pen Morfa Adit.
📸: Great Orme Mines director Edric Roberts alongside Marcus in one of the big stopes above Pen Morfa.
📸: Don Smith author of "The Great Orme Copper Mines" pictured emerging from the adit.
📸: Black and white image of the adit.