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Ynys Pit & Leat is a post-medieval aqueduct located in Wales, built to serve the industrial demands of coal extraction and processing in the region. The structure was engineered to transport water across the landscape, a critical resource for mining and mineral working operations that exploited the rich coal seams underlying the site. The bedrock geology comprises the South Wales Middle Coal Measures Formation, a sequence of mudstone, siltstone, sandstone and coal laid down during the Moscovian period of the Carboniferous. These productive strata also contained seams of ironstone and ferricrete, making the locality valuable for both coal and iron industries during the post-medieval and modern periods.
The leat—an artificial watercourse—represents a substantial engineering investment typical of industrial-era Wales, where water management was essential to fuel-hungry operations. Such structures conveyed water from upland sources to pit workings and processing sites in the valleys below. The Ynys Pit & Leat exemplifies the landscape transformation wrought by intensive mineral extraction, leaving visible traces of both extraction infrastructure and the water systems upon which it depended.
The monument is protected by Cadw under reference GM461, recognising its significance to the industrial heritage of Wales and its role in the region's economic history.
Ynys Pit & Leat is a scheduled monument protected by Cadw under reference GM461. View the official record →
Ynys Pit & Leat is a post-medieval aqueduct located in Wales, built to serve the industrial demands of coal extraction and processing in the region. It is designated a Scheduled Ancient Monument by Cadw under reference GM461.
Ynys Pit & Leat dates from the post medieval/modern period, and is classified as a aqueduct. It is one of over 32,000 scheduled monuments protected across the UK.
Ynys Pit & Leat 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 GM461.
Several scheduled monuments lie within 10 km, including Clyne Valley Shaft Mounds (0.4 km), Clyne Wood Coal Level (0.8 km), Clyne Wood Colliery Steam Winding Machine (0.9 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Ynys Pit & Leat'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.
Ynys Pit & Leat 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.