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Caer Carreg y Fran is a prehistoric hillfort located in Wales and protected by Cadw under reference CN058. The site occupies high ground composed of Neoproterozoic felsic tuff, a hard volcanic rock formed over 540 million years ago during the late Precambrian period. This ancient bedrock provided a naturally defensible foundation for settlement and would have offered resistance to erosion and quarrying by its builders.
The hillfort represents a significant phase of prehistoric fortification in the Welsh landscape. Sites of this type typically date to the Iron Age, though some show evidence of earlier Bronze Age origins. The elevated position and volcanic substrate at Caer Carreg y Fran would have afforded clear views across the surrounding terrain, essential for both defence and economic control of resources in the prehistoric period.
The monument's survival into the present day, despite millennia of exposure to the Welsh climate, reflects the durability of its volcanic bedrock. The tuff underlying the site would have weathered slowly compared to softer stones, preserving the archaeological features of this ancient settlement. Today Caer Carreg y Fran remains an important record of Iron Age settlement patterns and defensive strategies in prehistoric Wales.
Caer Carreg y Fran is a scheduled monument protected by Cadw under reference CN058. View the official record →
Caer Carreg y Fran is a prehistoric hillfort located in Wales and protected by Cadw under reference CN058.
Caer Carreg y Fran dates from the prehistoric period, and is classified as a hillfort. It is one of over 32,000 scheduled monuments protected across the UK.
Caer Carreg y Fran 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 CN058.
Several scheduled monuments lie within 10 km, including Drws y Coed Prehistoric Settlement (9.1 km), Drws y Coed Copper Mine (9.3 km), Small Fort Near Nantlle (9.4 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Caer Carreg y Fran'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.
Caer Carreg y Fran stands on Unnamed Extrusive Rocks, Neoproterozoic, bedrock that formed in the Neoproterozoic. The rock here is felsic tuff.