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Cairns on Pen Plynlimon-Arwystli is a prehistoric round cairn situated in Wales on bedrock comprising mudstone, siltstone and sandstone of the Ashgill formation. These Ordovician rocks underlie the upland terrain where the monument stands, their weathered surface providing the stony material from which the cairn was constructed. Round cairns of this type typically date to the Bronze Age and served as burial monuments, often marking significant locations within the prehistoric landscape. The construction method—heaping local stone—was practical and durable, allowing such monuments to survive millennia on exposed Welsh hillsides.
The cairn's survival into the modern period testifies to its solid construction and remote location on the Plynlimon-Arwystli ridge. Such elevated positions were favoured for Bronze Age burial cairns across Wales and the broader upland zones of Britain, suggesting importance or territorial significance. The monument remains a tangible link to the funerary practices and land use patterns of prehistoric communities in mid-Wales. It is protected by Cadw, the Welsh historic monuments service, under reference CD035, ensuring its preservation for future study and public understanding.
Cairns on Pen Plynlimon-Arwystli is a scheduled monument protected by Cadw under reference CD035. View the official record →
Cairns on Pen Plynlimon-Arwystli is a prehistoric round cairn situated in Wales on bedrock comprising mudstone, siltstone and sandstone of the Ashgill formation. It is designated a Scheduled Ancient Monument by Cadw under reference CD035.
Cairns on Pen Plynlimon-Arwystli dates from the prehistoric period, and is classified as a round cairn. It is one of over 32,000 scheduled monuments protected across the UK.
Cairns on Pen Plynlimon-Arwystli 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 CD035.
Several scheduled monuments lie within 10 km, including Cae Gaer (6 km), Llys Arthur, Dyffryn-Castell (6 km), Y Garnedd, Hirnant (7.2 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Cairns on Pen Plynlimon-Arwystli'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.
Cairns on Pen Plynlimon-Arwystli stands on Ashgill Rocks (Undifferentiated), bedrock that formed in the Ashgill. The rock here is mudstone, siltstone and sandstone.