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Pen y Dinas Cairn is a prehistoric round cairn situated on Lower Cambrian bedrock composed of sandstone and conglomerate deposits laid down in the Early Cambrian period. The monument occupies ground where ancient rocks, interbedded in alternating layers, form the natural foundation. Round cairns of this type are characteristic of Bronze Age funerary practice across Britain and Wales, typically constructed from stone gathered locally and heaped over cremated remains or inhumations.
The cairn's location on Early Cambrian geology means its builders would have drawn material from the surrounding landscape where weathered stone outcrops and loose fragments of sandstone and conglomerate were readily available. The natural bedrock here provided both a stable base for the monument and a convenient source of building stone, a pattern seen repeatedly at prehistoric sites constructed in areas of exposed or broken stone.
Pen y Dinas Cairn is protected by Cadw, the Welsh Historic Monuments service, under the reference ME236. This designation recognises its significance as a surviving example of prehistoric monumental construction and its importance to understanding Bronze Age burial practices and settlement patterns in Wales.
Pen y Dinas Cairn is a scheduled monument protected by Cadw under reference ME236. View the official record →
Pen y Dinas Cairn is a prehistoric round cairn situated on Lower Cambrian bedrock composed of sandstone and conglomerate deposits laid down in the Early Cambrian period. It is designated a Scheduled Ancient Monument by Cadw under reference ME236.
Pen y Dinas Cairn 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.
Pen y Dinas Cairn 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 ME236.
Several scheduled monuments lie within 10 km, including Cyfannedd-Fach Homestead (8.8 km), Bron-Llety-Ifan cairns and cup-marked rock (9 km), Fairbourne Anti-invasion Defences (9 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Pen y Dinas Cairn'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.
Pen y Dinas Cairn stands on Lower Cambrian Rocks (Undifferentiated), bedrock that formed in the Early Cambrian. The rock here is sandstone and conglomerate, interbedded.