1. A group of relict shaft mound features for early coal mining. These examples are most likely to represent small bell-pits for primitive digging of coal seams near the surface. Possibly dated from the eighteenth century.
Source: Cadw scheduling text.

2. An area of earthworks from bell pits or shallow shaft working in the eighteenth and nineteenth centuries.
(Source: Collieries of Wales, RCAHMW)
B.A.Malaws, RCAHMW, 26 May 2011.