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Offa's Dyke: Sections N & S of Bryn yr Owen Colliery is an early medieval linear earthwork forming part of the monumental frontier constructed between Wales and England during the 8th century. The dyke at this location runs across terrain underlain by the Pennine and South Wales Middle Coal Measures Formation, a Moscovian-age bedrock comprising mudstone, siltstone, sandstone, coal, ironstone and ferricrete. These robust strata would have presented considerable engineering challenges to the labour forces constructing the earthwork, yet the dyke was built to endure as a physical boundary marker across the landscape.
The northern and southern sections preserved at Bryn yr Owen Colliery represent surviving stretches of what was once an extensive earthwork system. The monument's survival in this industrial area, despite the geological complexity of the underlying coal-bearing formations, testifies to the scale and durability of early medieval frontier engineering. The site remains protected by Cadw as a scheduled monument of national significance, acknowledging its importance to understanding medieval settlement patterns and territorial organisation in the Welsh Marches region.
Offa's Dyke: Sections N & S of Bryn yr Owen Colliery is a scheduled monument protected by Cadw under reference DE179. View the official record →
Offa's Dyke: Sections N & S of Bryn yr Owen Colliery is an early medieval linear earthwork forming part of the monumental frontier constructed between Wales and England during the 8th century. It is designated a Scheduled Ancient Monument by Cadw under reference DE179.
Offa's Dyke: Sections N & S of Bryn yr Owen Colliery 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: Sections N & S of Bryn yr Owen Colliery 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 DE179.
Several scheduled monuments lie within 10 km, including Offa's Dyke: Section N & S of Tan-y-Cut (6.4 km), Offa's Dyke: Section N & S of Plas-Offa (6.9 km), Pontcysyllte Aqueduct and Canal (7.2 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Offa's Dyke: Sections N & S of Bryn yr Owen Colliery'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: Sections N & S of Bryn yr Owen Colliery 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.