View from north east (Scale 1m).
Nant y Wern also known as Pant Serthfa is a single stone row measuring at least 5.95m and possibly 54m long, including at least four or six small and medium-sized stones situated on a gentle south facing slope. The row is orientated north to south and is built across the limit of visibility to Cefn yr Ystrad. The row is also at the limit of visibility to Pen y Fan.
Plan of Nant y Wern (Pant Serthfa) stone row (Source: survey by Sandy Gerrard at 1:100).