© Mapbox · © OpenStreetMap contributors · Boundary data © Cadw
Allt-y-Ferin Mound and Bailey Castle is a prehistoric hillfort situated in Wales, built upon bedrock of Ashgill mudstone, siltstone and sandstone. The site is protected by Cadw as a scheduled ancient monument under reference CM157. The geological foundation provided relatively stable ground for defence works, though the soft sedimentary bedrock would have required substantial timber reinforcement in any structural elements.
The monument comprises both mound and bailey earthworks, indicating a settlement designed for both habitation and defence during the Iron Age or earlier prehistoric period. The combination of these two elements suggests a two-phase development or the use of distinct functional areas within the fortified enclosure. Such hillforts typically exploited elevated terrain to maximise visibility across surrounding lowlands.
The site's survival into the modern period, despite its ancient origins, reflects its location in the Welsh landscape where many such monuments remain as significant archaeological and historical features. The earthworks visible today represent centuries of accumulated soil deposit and erosion, though their original defensive capacity would have been more pronounced. Cadw's protection ensures the preservation of this prehistoric settlement for future study and public understanding.
Allt-y-Ferin Mound and Bailey Castle is a scheduled monument protected by Cadw under reference CM157. View the official record →
Allt-y-Ferin Mound and Bailey Castle is a prehistoric hillfort situated in Wales, built upon bedrock of Ashgill mudstone, siltstone and sandstone. It is designated a Scheduled Ancient Monument by Cadw under reference CM157.
Allt-y-Ferin Mound and Bailey Castle dates from the prehistoric period, and is classified as a hillfort. It is one of over 32,000 scheduled monuments protected across the UK.
Allt-y-Ferin Mound and Bailey Castle 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 CM157.
Several scheduled monuments lie within 10 km, including Pen y Cnap Castle (2 km), Ffynnon-Newydd Standing Stones (3.4 km), Maes y Crug round barrow (3.6 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Allt-y-Ferin Mound and Bailey Castle'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.
Allt-y-Ferin Mound and Bailey Castle stands on Ashgill Rocks (Undifferentiated), bedrock that formed in the Ashgill. The rock here is mudstone, siltstone and sandstone.