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Wat's Dyke: Section W of Garreg-Lwyd is an early medieval linear earthwork forming part of the longer Wat's Dyke system in Wales. This section occupies ground underlain by Pennine and South Wales Lower Coal Measures, a sequence of mudstone, siltstone and sandstone deposits laid down during the Westphalian period, with interbedded coal and ironstone. The variable geology of this coalfield landscape influenced the construction and survival of the earthwork as it crosses the terrain.
The dyke represents a significant boundary demarcation of the early medieval period, constructed as a substantial linear bank and ditch. The harder sandstone and ferricrete bands within the underlying bedrock would have affected both the ease of construction and the long-term preservation of the monument. Such geological variation across the site's footprint creates distinctive sections in the surviving earthwork.
The monument is protected by Cadw, the Welsh heritage protection agency, under the reference FL087. As a surviving segment of an extensive linear system, this section contributes valuable evidence to understanding early medieval land division, territorial control and engineering practices in Wales during the formation of political boundaries that shaped the medieval kingdom.
Wat's Dyke: Section W of Garreg-Lwyd is a scheduled monument protected by Cadw under reference FL087. View the official record →
Wat's Dyke: Section W of Garreg-Lwyd is an early medieval linear earthwork forming part of the longer Wat's Dyke system in Wales. It is designated a Scheduled Ancient Monument by Cadw under reference FL087.
Wat's Dyke: Section W of Garreg-Lwyd 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.
Wat's Dyke: Section W of Garreg-Lwyd 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 FL087.
Several scheduled monuments lie within 10 km, including Offa's Dyke: Section S from Pen y Coed (8.2 km), Offa's Dyke: Mountain View Section (8.3 km), Brymbo Lead Smelting Works (8.6 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Wat's Dyke: Section W of Garreg-Lwyd'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.
Wat's Dyke: Section W of Garreg-Lwyd stands on Pennine Lower Coal Measures Formation And South Wales Lower Coal Measures Formation (Undifferentiated), bedrock that formed in the Westphalian. The rock here is mudstone, siltstone, sandstone, coal, ironstone and ferricrete.