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Bwlch y Clawdd Dyke is a linear earthwork of unknown date and purpose located in Wales. The monument comprises a substantial bank and ditch that traverses the landscape, a form of construction typical of prehistoric and medieval frontier defences, though its precise chronology remains undetermined. The earthwork is preserved in situ across bedrock of the South Wales Upper Coal Measures Formation, a sequence of Westphalian age composed of mudstone, siltstone and sandstone interstratified with coal seams and ironstone deposits. This underlying geology would have influenced both the construction technique and subsequent erosion patterns of the dyke.
The monument is protected by Cadw, the Welsh Historic Monuments service, under the reference GM500, reflecting its archaeological significance as a landscape feature. Linear earthworks of this type frequently formed territorial boundaries, defensive lines or stock enclosures, though without associated datable artefacts or archaeological investigation, the specific function of Bwlch y Clawdd Dyke remains uncertain. Its survival as an upstanding feature offers potential for future study to establish its age and role within the local settlement and land-use history of Wales.
Bwlch y Clawdd Dyke is a scheduled monument protected by Cadw under reference GM500. View the official record →
Bwlch y Clawdd Dyke is a linear earthwork of unknown date and purpose located in Wales. It is designated a Scheduled Ancient Monument by Cadw under reference GM500.
Bwlch y Clawdd Dyke dates from the unknown period, and is classified as a linear earthwork. It is one of over 32,000 scheduled monuments protected across the UK.
Bwlch y Clawdd Dyke 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 GM500.
Several scheduled monuments lie within 10 km, including Mynydd Ton Cairns (0.9 km), Carn y Hyrddod & Neighbouring Cairn (2.3 km), Mynydd y Gelli kerb cairn (3.6 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Bwlch y Clawdd Dyke'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.
Bwlch y Clawdd Dyke stands on South Wales Upper Coal Measures Formation, bedrock that formed in the Westphalian. The rock here is mudstone, siltstone, sandstone, coal, ironstone and ferricrete.