It’s a good half-mile inside a mid-Wales mountain and Al Tansey and Ioan Lord have worked their way through several levels, squeezed past narrow shafts, over collapsed chambers and abseiled down some 900 feet. Water drips from the chiseled pit roof just above their heads and below are holes, hundreds of feet deep, down to submerged champers and rock faces where men and children did back-breaking work, 12 hours a day, six days a week if they were lucky, seven if not. National Library celebrate iconic couple's life on screen at Broadcast Archive event The Scots are stealing our Welsh Stonehenge stones as their own, says new study Aberystwyth professor launches search for first episode of 'Pobl y Cwm' Tributes paid to Dewi 'Pws' Morris “About half of the men and boys who died in these mines fell to their deaths,” says Al, his words cutting through the flickering and faint shadows cast from his tallow candle.

A second candle burns, held by fellow explorer Ioan. “This is all you can see and it’s very difficult to see the ground. That’s why do many fell to their deaths,” Ioan says.

“They just couldn’t see.” Numbers on those who died are hard to research, but the two men are determined that they will record and preserve for future generations the long mining traditions of west and mid Wales. Since the Bronze Age, men have opened up holes in the ground and hillsides, venturing into a dark, damp and dangerous abyss to extract minerals needed to make and trade, prod.