Nant y Gro ciarns comprises the remains of two small cairns, 9 meters apart, on the north-east facing flanks of Y Gamriw. The cairn to the east measures 4m in diameter and 0.2m in height and that on the west measures 3m in diameter and 0.2m in height.
The importance of the monument is enhance by the other scheduled monuments in the area, including the Ty'n y Pant round cairns (BR377) and the Crugiau Bach stone circle (BR274) situated about 100m to the east-south-east.
Source: Cadw scheduling description of February 2008.
RCAHMW 29.02.2008