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Graig Fawr is a prehistoric hillfort situated in Wales, occupying a commanding position on geology of the South Wales Upper Coal Measures Formation. The underlying bedrock comprises mudstone, siltstone and sandstone interbedded with coal seams and ironstone, capped by ferricrete—the indurated iron-rich layer that gives the hilltop its natural strength and prominence. This solid foundation would have provided an exceptional platform for defensive earthworks.
The hillfort consists of substantial banks and ditches that define an enclosed settlement area. The earthwork defences follow the natural contours of Graig Fawr, where the steep slopes and resistant capping geology offered additional protection. The durable nature of the ferricrete bedrock would have resisted erosion, preserving the form of these prehistoric structures through subsequent millennia.
The monument is protected by Cadw, the Welsh Historic Monuments service, under reference GM386, recognising its archaeological and historical significance. Hillforts of this type typically date to the Iron Age, serving as focal points for territorial control, storage and communal defence across the Welsh landscape. The prominence of Graig Fawr within its local topography suggests this settlement held considerable strategic importance for its contemporary inhabitants.
Earthwork on Graig Fawr is a scheduled monument protected by Cadw under reference GM386. View the official record →
Graig Fawr is a prehistoric hillfort situated in Wales, occupying a commanding position on geology of the South Wales Upper Coal Measures Formation. It is designated a Scheduled Ancient Monument by Cadw under reference GM386.
Earthwork on Graig Fawr dates from the prehistoric period, and is classified as a hillfort. It is one of over 32,000 scheduled monuments protected across the UK.
Earthwork on Graig Fawr 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 GM386.
Several scheduled monuments lie within 10 km, including Llandeilo Castle Mound (5.2 km), Earthwork 1080m NNW of Fforest Newydd (5.6 km), Remains of Astronomical Observatory at Penllergaer (7.8 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Earthwork on Graig Fawr'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.
Earthwork on Graig Fawr 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.