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Nant-y-Mwyn Lead Mine Engine House, Rhandir-Mwyn is a post-medieval industrial structure built to exploit the mineral resources of the surrounding Ashgill bedrock. The engine house sits on mudstone, siltstone and sandstone formations laid down in the Ashgill period, strata that host the lead mineralisation worked in this upland Welsh location. Such geological conditions made this area attractive to miners seeking metallic ores throughout the modern period.
The engine house represents the technological shift that transformed lead mining in Wales during the industrial era. These buildings housed the steam engines that powered the pumps and winding gear essential for extracting ore from ever-deeper seams and managing water ingress in underground workings. The structure demonstrates the scale and permanence of investment required for successful mining operations beyond the reach of simple hand labour.
Now protected by Cadw under reference CM215, the engine house survives as evidence of Wales's significant role in industrial-era metal extraction. Standing within the Rhandir-Mwyn landscape, it marks a site where geological opportunity and industrial innovation intersected, drawing capital and labour to this remote upland location to unlock the valuable deposits held within the ancient bedrock beneath.
Nant-y-Mwyn Lead Mine Engine House, Rhandir-Mwyn is a scheduled monument protected by Cadw under reference CM215. View the official record →
Nant-y-Mwyn Lead Mine Engine House, Rhandir-Mwyn is a post-medieval industrial structure built to exploit the mineral resources of the surrounding Ashgill bedrock. It is designated a Scheduled Ancient Monument by Cadw under reference CM215.
Nant-y-Mwyn Lead Mine Engine House, Rhandir-Mwyn dates from the post medieval/modern period, and is classified as a engine house. It is one of over 32,000 scheduled monuments protected across the UK.
Nant-y-Mwyn Lead Mine Engine House, Rhandir-Mwyn 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 CM215.
Several scheduled monuments lie within 10 km, including Bryn-Poeth-Uchaf, ring cairn to NE of (1.2 km), Stone Circle 200m SW of Cerrig Cynant (1.4 km), Bryn-Poeth-Uchaf, ring cairn to ESE of (1.5 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Nant-y-Mwyn Lead Mine Engine House, Rhandir-Mwyn'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.
Nant-y-Mwyn Lead Mine Engine House, Rhandir-Mwyn stands on Ashgill Rocks (Undifferentiated), bedrock that formed in the Ashgill. The rock here is mudstone, siltstone and sandstone.