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Castell Glas Castle Mound is a medieval motte situated in Wales and protected by Cadw as a scheduled monument under reference MM190. The earthwork represents a common form of Norman fortification deployed across Britain and Wales during the medieval period, consisting of a raised mound that once supported a timber or masonry structure. The motte functioned as both a defensive stronghold and a symbol of lordly authority over the surrounding landscape.
The mound rises from bedrock of the Lias Group, a geological formation comprising mudstone, siltstone, limestone and sandstone deposited during the Aalenian period. This Jurassic substrate provided a stable foundation for the castle's construction, though the softer clay and silt components would have required careful drainage to prevent the mound from becoming unstable in wet conditions. The choice of site reflects medieval builders' understanding of local geology and hydrology.
The survival of this earthwork, despite centuries of agricultural use and weathering, testifies to the solidity of its original construction. Mottes of this type typically occupied strategic positions controlling communication routes, river crossings or territorial boundaries. Castell Glas remains an important archaeological record of medieval settlement and military organisation in Wales, preserving evidence of the period when Norman and Welsh lordships shaped the region's political geography.
Castell Glas Castle Mound is a scheduled monument protected by Cadw under reference MM190. View the official record →
Castell Glas Castle Mound is a medieval motte situated in Wales and protected by Cadw as a scheduled monument under reference MM190.
Castell Glas 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.
Castell Glas 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 MM190.
Several scheduled monuments lie within 10 km, including Tredegar Fort (1.6 km), Gwern y Cleppa Burial Chamber (2.6 km), Newport Castle (2.9 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Castell Glas 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.
Castell Glas Castle Mound stands on Lias Group, bedrock that formed in the Aalenian. The rock here is mudstone, siltstone, limestone and sandstone.