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Carn Alw Hillfort is a prehistoric defensive settlement occupying high ground in Wales. The fort exploits the natural defensive properties of its elevated position and underlying bedrock of Ordovician felsic tuff, an extrusive volcanic rock that would have provided a firm foundation for rampart construction and naturally rocky outcrops to complement artificial defences. This geological substrate, formed during the Ordovician period over 450 million years ago, creates the characteristic landscape in which the hillfort sits.
The monument demonstrates the strategic use of topography and geology typical of Welsh hillforts, where settlements were positioned to command views across surrounding valleys and territory. The volcanic tuff bedrock would have offered exposed stone suitable for building, reducing the labour required to quarry materials for defensive works and domestic structures.
Carn Alw Hillfort is protected by Cadw, the Welsh historic monuments authority, under the reference PE375. The site remains an important archaeological record of prehistoric settlement patterns and the relationship between Iron Age and earlier communities and their natural environment in Wales.
Carn Alw Hillfort is a scheduled monument protected by Cadw under reference PE375. View the official record →
Carn Alw Hillfort is a prehistoric defensive settlement occupying high ground in Wales. It is designated a Scheduled Ancient Monument by Cadw under reference PE375.
Carn Alw Hillfort dates from the prehistoric period, and is classified as a hillfort. It is one of over 32,000 scheduled monuments protected across the UK.
Carn Alw Hillfort 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 PE375.
Several scheduled monuments lie within 10 km, including Earthwork 125m South West of Meini Gwyr (7.2 km), Tumulus N of Goodwins Row, Efailwen (7.5 km), Pant y Menyn Round Barrow (7.6 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Carn Alw Hillfort'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.
Carn Alw Hillfort stands on Unnamed Extrusive Rocks, Ordovician, bedrock that formed in the Ordovician. The rock here is felsic tuff.