Extensive remains of features related to nineteenth-century rabbit farming are located on the south-east facing moorland slopes above the Cray Reservoir and Nant Tywynni, spanning an area of 2km NE-SW by 0.75km. The southern extent of this complex includes three pit traps, two pillow mounds, a linear bank and a drainage ditch (NPRN 84911).
The greater part lies in map quarter sheet SN82SE. Early air photo transcription and Ordnance Survey investigation suggests here there may be at least 40 further pillow mounds and perhaps 5-10 pit traps. Although most of these features are visible on recent air photos only 14 pillow mounds have so far been verified on the ground.
Features related to rabbit farming also lie to the south-west within a walled enclosure at the southern end of Cefn Cul and are reported as a separate farm (84382) though both may have been managed as one. The warrens are thought to have been established between 1827 & 1859.

Additional sources:
OS Record: SN82SE3.
Antiquity Model @ 1:10000 scale for SN82SE (part).

D.Leighton & B.A.Malaws, RCAHMW, 21 July 2015