The site was dug into the mountain with large banks around a square yard to cover it up from the outside world. The site had the usual mine buildings, an office, lamproom, coal processing facilities and a weighbridge.

The 2 drifts ran South West into the bottom of a partially exposed rock face which still show evidence of a thin seam in towards the top.

As of 2024 the site has been mostly cleared and the drifts filled. Some random mining debris such as pipes, ventilation tubs and wires litter the site. The Johnson mine sign is partially intact at the entrance on Forgeside road.

1988-93 Griffin and Son (Pwll Du) Ltd
1993-98 Ffynonau Duon Mines Ltd
1998 Abandoned
2008-13 Riche UK Mining Ltd

Worked the Big and 4ft Seams

Site is on access land and can be reached by walking up the old entrance road.