Cwm-nant-ddu colliery was sunk in about 1860, initially to work ironstone and, subsequently, coal. Cwm-nant-ddu later became known as Llanerch colliery. It was the site of an underground explosion on the 6th of February 1890, which resulted in the deaths of 176 men and boys. The mine closed in 1947. No surface buildings remain on the site.

Sources :
Glamorgan Gwent Archaeological Trust , 1992 , Blaenserchan Colliery Reclamation Scheme
GGAT Blaenserchan Assessment A069

RCAHMW, 2015.