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Pen y Gaer is a prehistoric hillfort situated in Wales and protected by Cadw as a scheduled monument under reference CM101. The fort occupies a commanding position built upon bedrock of Llandovery age, comprising mudstone, siltstone and sandstone formations characteristic of this early Paleozoic geological period. These durable rock strata provided a stable foundation for the settlement's construction and would have influenced how its defences were engineered and maintained.
The hillfort's location reflects the strategic importance of elevated terrain in prehistoric Wales, offering views across the surrounding landscape and natural defensive advantages. The underlying geology, with its alternating layers of mudstone and sandstone, would have shaped the character of the site itself, determining the depth and nature of any ditches or ramparts and the availability of stone for building and reinforcement.
As a scheduled monument in Wales, Pen y Gaer remains subject to protection and archaeological control. The site preserves evidence of prehistoric settlement patterns and defensive strategies characteristic of Iron Age hillforts in the Welsh uplands, though its full chronology and the extent of its occupation remain matters for archaeological investigation.
Pen y Gaer is a scheduled monument protected by Cadw under reference CM101. View the official record →
Pen y Gaer is a prehistoric hillfort situated in Wales and protected by Cadw as a scheduled monument under reference CM101.
Pen y Gaer dates from the prehistoric period, and is classified as a hillfort. It is one of over 32,000 scheduled monuments protected across the UK.
Pen y 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 CM101.
Several scheduled monuments lie within 10 km, including Derlwyn round barrow cemetery (2.5 km), Pant-Teg Standing Stone (4 km), Crugiau Edryd Round Barrows (4.1 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Pen y 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.
Pen y Gaer stands on Llandovery Rocks (Undifferentiated), bedrock that formed in the Llandovery. The rock here is mudstone, siltstone and sandstone.