© Mapbox · © OpenStreetMap contributors · Boundary data © Cadw
St Harmon Roman road is a Roman road in Wales, protected by Cadw under reference RD261. The road was constructed across terrain underlain by Llandovery bedrock, a sequence of mudstones, siltstones and sandstones dating to the Llandovery period. This geology would have presented significant challenges to Roman road builders, as the fine-grained rocks are susceptible to weathering and movement on sloping ground, requiring careful engineering of drainage and foundations.
The route traverses the upland landscape of central Wales, where Roman military infrastructure connected forts and settlements across difficult terrain. Roman roads in Wales typically followed strategic lines established during the conquest and consolidation of the province, linking garrison sites with communication routes that facilitated troop movement and supply lines through less densely settled regions.
The survival of this road as an archaeological monument reflects both the durability of Roman construction methods and the relative stability of the upland environment. The mudstone and siltstone bedrock, whilst weathered, has protected traces of the original road structure beneath the modern landscape. As a protected Cadw monument, St Harmon Roman road remains an important record of Roman military engineering and the Roman presence in Wales.
St Harmon Roman road is a scheduled monument protected by Cadw under reference RD261. View the official record →
St Harmon Roman road is a Roman road in Wales, protected by Cadw under reference RD261.
St Harmon Roman road dates from the roman period, and is classified as a road. It is one of over 32,000 scheduled monuments protected across the UK.
St Harmon Roman road is a Scheduled Ancient Monument, legally protected by Cadw — the body responsible for designating and safeguarding heritage sites in Wales. The official designation reference is RD261.
Several scheduled monuments lie within 10 km, including Round Cairn 130m E of Cryn-Fryn (9.3 km), Corn Drying Kiln 340m S of Cryn-Fryn (9.7 km), Banc Ystrad-wen cairn cemetery (10 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of St Harmon Roman road's history, each drawn from the record and mapped to the exact spot:
Every location is different. Not every section appears for every place, only what the historical record actually holds turns up in a report.
St Harmon Roman road stands on Llandovery Rocks (Undifferentiated), bedrock that formed in the Llandovery. The rock here is mudstone, siltstone and sandstone.