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Maen Gwyn Hir is a prehistoric standing stone situated in Wales and protected as a scheduled monument by Cadw under reference CM094. The stone rises from bedrock of Ashgill mudstone, siltstone and sandstone, formed during the Ashgill period in the late Ordovician, deposits that underlie much of the surrounding landscape. Such undifferentiated Ashgill rocks provide the local geological character throughout this region, their weathered surface and natural fracturing having shaped the terrain in which this monument stands.
The stone belongs to a tradition of upright monoliths erected across Britain and Ireland during the Neolithic and Bronze Age periods. These monuments typically served ritual, ceremonial or territorial purposes within early farming communities, though their precise functions remain subject to interpretation. Their prominence in the landscape—visible from considerable distances—suggests they held significance beyond the purely practical.
Standing stones of this type are found across Wales, where they form part of the broader prehistoric ritual landscape. The placement of Maen Gwyn Hir within its geological setting, rising from the Ashgill bedrock, anchors it within the material world of its constructors, whose knowledge of local stone resources and landscape would have guided such monumental undertakings.
Maen Gwyn Hir is a scheduled monument protected by Cadw under reference CM094. View the official record →
Maen Gwyn Hir is a prehistoric standing stone situated in Wales and protected as a scheduled monument by Cadw under reference CM094.
Maen Gwyn Hir dates from the prehistoric period, and is classified as a standing stone. It is one of over 32,000 scheduled monuments protected across the UK.
Maen Gwyn Hir 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 CM094.
Several scheduled monuments lie within 10 km, including Castell Mawr Mound and Bailey Castle (2.9 km), Crug Hywel Round Barrow (4.4 km), Pant-Glas Round Barrow (4.7 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Maen Gwyn Hir'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.
Maen Gwyn Hir stands on Ashgill Rocks (Undifferentiated), bedrock that formed in the Ashgill. The rock here is mudstone, siltstone and sandstone.