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Cwmbyrgwm Colliery is a post-medieval and modern coal mine located in Wales, protected as a scheduled monument by Cadw under reference MM163. The site exploits the South Wales Upper Coal Measures Formation, a geological sequence of rocks laid down during the Westphalian period. These strata comprise alternating mudstone, siltstone and sandstone interbedded with workable coal seams, alongside deposits of ironstone and ferricrete, which accumulated in a deltaic environment hundreds of millions of years ago.
The colliery represents the intensive mineral extraction that transformed South Wales during the industrial era, when advances in mining technology and transport infrastructure made deep coal working economically viable. The Upper Coal Measures here supported both the region's coal industry and associated iron production, resources that powered the Industrial Revolution across Britain and beyond.
As a scheduled monument, Cwmbyrgwm Colliery is recognised for its historical significance in documenting Wales's industrial heritage. The site preserves physical evidence of extraction methods, infrastructure and the relationship between geology and industrial development that characterised this landscape for nearly two centuries.
Cwmbyrgwm Colliery is a scheduled monument protected by Cadw under reference MM163. View the official record →
Cwmbyrgwm Colliery is a post-medieval and modern coal mine located in Wales, protected as a scheduled monument by Cadw under reference MM163.
Cwmbyrgwm Colliery dates from the post medieval/modern period, and is classified as a coal mine. It is one of over 32,000 scheduled monuments protected across the UK.
Cwmbyrgwm 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 MM163.
Several scheduled monuments lie within 10 km, including Air Furnace at British Ironworks (0.7 km), British Colliery Pumping Engine House (0.8 km), Abersychan Railway (2.6 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Cwmbyrgwm 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.
Cwmbyrgwm Colliery 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.