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St Mary's Yard Castle Mound is a medieval motte situated in Wales and protected by Cadw under reference MM082. The earthwork rises from bedrock composed of Pridoli rocks—undifferentiated mudstone, siltstone and sandstone deposited during the Pridoli epoch. This underlying geology would have provided a stable foundation for construction, though the softer sedimentary character of the bedrock differs from the harder volcanic or igneous substrates found beneath some contemporary Welsh fortifications. The motte's positioning exploited the natural topography of its site, a common practice in Norman and early medieval castle design.
The mound represents a widespread form of military architecture introduced into Wales during the medieval period, when earthwork fortifications offered rapid, cost-effective defensive solutions. Mottes of this era typically served administrative and military functions for their lords, dominating the surrounding landscape and providing visibility across productive lowland terrain. St Mary's Yard's specific location within its local geography would have been chosen to command communication routes or secure valuable resources.
The monument survives as a significant archaeological record of medieval settlement and territorial control in Wales. Although the mound no longer carries visible stone structures, it preserves evidence of medieval landscape organisation beneath its grass-covered slopes and remains a physical reminder of the period when such fortified earthworks marked the boundaries of Norman and Welsh lordship.
St Mary's Yard Castle Mound is a scheduled monument protected by Cadw under reference MM082. View the official record →
St Mary's Yard Castle Mound is a medieval motte situated in Wales and protected by Cadw under reference MM082.
St Mary's Yard Castle Mound dates from the medieval period, and is classified as a motte. It is one of over 32,000 scheduled monuments protected across the UK.
St Mary's Yard Castle Mound 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 MM082.
Several scheduled monuments lie within 10 km, including Coed y Bwnydd Camp (1.6 km), Bettws Newydd Churchyard Cross-Base (1.6 km), St. David's Churchyard Cross, Trostre (2.7 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of St Mary's Yard Castle Mound'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.
St Mary's Yard Castle Mound stands on Pridoli Rocks (Undifferentiated), bedrock that formed in the Pridoli. The rock here is mudstone, siltstone and sandstone.