Distinct and well preserved earthworks of part of the Roman road running south of Tomen-y-Mur (RR69b - NPRN 303520). This segment of the road runs for about 245m either side of the Nant Goch at Pen-y-Stryd (SH72643201 to SH72703178). Some 390m to the north-north-west is a further segment, recorded under NPRN 300006.
South of the Nant Goch the road appears as an 'agger', or cambered roadway, 6.0m wide and perhaps 0.2m high, flanked by shallow 0.8-1.0m wide ditches. On a rise, some 15m to the east, is one of the Pen-y-Stryd Roman kilns (see NPRN 303042).
A hollow way approaching the Afon Gain, some 660m to the south-east, is labelled as 'Roman Road' on current OS mapping. However, the OS 1st edition County series (Merioneth. XX.15 1889) shows the road turning to run to the south-south-west beyond the recorded segment.
John Wiles 30.05.07

A raised, linear earthwork, 5m to 6m wide, with shallow 1.5m wide flanking ditches. These are the visible earthworks of Sarn Helen Roman road. M. Evans, University of Sheffield, 31 March 2009.