DisgrifiadCoity Mawr Quarry (nprn 67670) was worked from the 1830s and is shown on the 1844 Tithe map. Later, a coal level was driven at the base of the quarry. It, and the air shaft, are shown on the 1st ed OS.
Vertical shaft 1.5m diameter, fenced off. At the top is a simple derrick comprising a pole to which a pulley block has been fixed.
R Hayman, Hayman & Horton, 8/1/2003