© Mapbox · © OpenStreetMap contributors · Boundary data © Cadw
Offa's Dyke: Section in Plas Power Park is an early medieval linear earthwork that forms part of the substantial defensive boundary constructed along the Wales-England frontier. The monument comprises a characteristic bank-and-ditch structure typical of eighth-century construction, where an upcast bank was raised from an adjacent ditch to create a prominent physical and symbolic barrier across the landscape.
The earthwork's preservation in Plas Power Park reflects the underlying geology of the South Wales coal measures, where mudstone, siltstone and sandstone bedrock provided stable ground for the substantial engineering required. The mineral-rich deposits in this coal measures formation, including coal and ironstone seams, shaped the wider economic significance of the borderland that Offa's Dyke traversed and defended.
The section is protected by Cadw as a scheduled ancient monument under reference DE180, recognising its national importance as one of the most significant surviving examples of early medieval earthwork engineering in Britain. The dyke's presence here demonstrates how the frontier boundary extended through varied terrain, adapting to local topography whilst maintaining its strategic function across the Welsh borderlands.
Offa's Dyke: Section in Plas Power Park is a scheduled monument protected by Cadw under reference DE180. View the official record →
Offa's Dyke: Section in Plas Power Park is an early medieval linear earthwork that forms part of the substantial defensive boundary constructed along the Wales-England frontier. It is designated a Scheduled Ancient Monument by Cadw under reference DE180.
Offa's Dyke: Section in Plas Power Park dates from the early medieval period, and is classified as a linear earthwork. It is one of over 32,000 scheduled monuments protected across the UK.
Offa's Dyke: Section in Plas Power Park 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 DE180.
Several scheduled monuments lie within 10 km, including Wat's Dyke: Section extending from Pentre-Clawdd to Wynnstay Park (6.6 km), Offa's Dyke: Section SW from Tatham Bridge (6.8 km), Wynnstay Colliery Walker Fan House (7 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Offa's Dyke: Section in Plas Power Park'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.
Offa's Dyke: Section in Plas Power Park stands on Pennine Middle Coal Measures Formation And South Wales Middle Coal Measures Formation (Undifferentiated), bedrock that formed in the Moscovian. The rock here is mudstone, siltstone, sandstone, coal, ironstone and ferricrete.