In the Brecon Beacons, approximately 10 miles north west of Merthyr Tydfil, on the eastern bank of the river Neath, is the deserted Blaen Nedd Fechan farmstead. 'It comprises a long range of three conjoined buildings, the central one a house with a gable fireplace. The other compartments are too ruined to interpret but were probably intended for animals. There was a narrow courtyard along the east flank.'
It seems likely that the farmstead was already abandoned by the time the 2nd edition of the 25inch OS maps was published in 1904. Although the map records the 'long range of three conjoined buildings,' the farmstead is unnamed. On modern editions of the OS maps, the range is no longer marked as being separated into three distinct buildings. Instead, The map records a rectangular outline conjoined to a triangular one on its southern side.
Sources: modern and historic OS maps; notes written by Paul R Davis relating to site visit conducted on 22nd February 2019
M. Ryder, RCAHMW, 8th May 2019