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Gron-Gaer is a prehistoric enclosure located in Wales and protected by Cadw under reference GM197. The monument occupies ground underlain by the South Wales Upper Coal Measures Formation, a bedrock sequence of Westphalian age comprising mudstone, siltstone, sandstone, coal, ironstone and ferricrete. This underlying geology would have shaped both the character of the landscape visible to its prehistoric builders and the practical constraints of constructing and maintaining the enclosure itself.
The site represents a type of prehistoric monument common across Wales and the broader British Isles, though the specific topography and geological substrate at Gron-Gaer give it local significance. Such enclosures typically functioned as settlement centres, stock management facilities, or places of ritual and communal gathering, their earthwork defences marking boundaries and controlling movement across the landscape.
The preservation of Gron-Gaer as a scheduled monument reflects its importance to understanding prehistoric settlement patterns and land use in this region of Wales. The visible earthworks remain a key source of archaeological evidence, even in the absence of extensive modern excavation, contributing to the wider picture of how prehistoric communities organised their lives and resources across the varied terrain of South Wales.
Gron-Gaer is a scheduled monument protected by Cadw under reference GM197. View the official record →
Gron-Gaer is a prehistoric enclosure located in Wales and protected by Cadw under reference GM197.
Gron-Gaer dates from the prehistoric period, and is classified as a enclosure. It is one of over 32,000 scheduled monuments protected across the UK.
Gron-Gaer 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 GM197.
Several scheduled monuments lie within 10 km, including Penmaen Burrows Church (6.9 km), Penmaen Burrows Burial Chamber (6.9 km), Penmaen Burrows Ringwork (6.9 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Gron-Gaer'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.
Gron-Gaer stands on South Wales Upper Coal Measures Formation, bedrock that formed in the Westphalian. The rock here is mudstone, siltstone, sandstone, coal, ironstone and ferricrete.