A cutting into the hillside, oriented NE-SW and at right-angles to Blaen y Cwm Road. It is 14m long, up to 8m wide and 2m deep, with water and thick reeds in the base and thin turf to the sides. The entrance is concealed beneath subsidence. Probably a coal level; a number of these are shown elsewhere on Cefn Crib Common on the 1886 OS map.
Recorded as part of RCAHMW Uplands Initiative Project, W B Horton, H & H, 16/08//2013.
