1.The quarry is cut into a natural outcrop of limestone on an east facing slope. The quarry is scoop-shaped. It is excavated into level ground and has a depth of 1.5m. It would appear that the quarry was formed to extract walling stone. Limestone quarry cut into a natural outcrop. Vertical face of stone. Sheep shelters at the base of the slope. The ground cover was bracken at the time of survey. B. Britton and G. Arnold, ArchaeoPhysica Ltd, 07/01/2009

2. The quarry produced a gritstone known as Twrch Sandstone, rather than limestone as noted above, as limestone is not present in this area except at greater depths.

(Source, e-mail from a member of staff at Brecon Beacons National Park, received 11.10.2019)