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Rhymney Upper Furnace is a post-medieval blast furnace located in Wales, protected by Cadw under reference GM403. The monument stands upon bedrock of the Pennine and South Wales Lower Coal Measures Formation, undifferentiated strata of Westphalian age. This geological foundation—comprising mudstone, siltstone, sandstone, coal, ironstone and ferricrete—provided the raw materials essential to iron smelting operations. The proximity of coal seams and ironstone deposits made this location strategically valuable for industrial development during the post-medieval period.
Blast furnaces of this era represent the technological advancement of iron production in Britain, where localised mineral resources could be exploited to fuel growing industrial demand. The Rhymney furnace exemplifies the integration of industrial infrastructure with the underlying geology, a relationship fundamental to the success of ironworks throughout Wales and the wider coalfield regions.
The monument survives as physical evidence of the region's industrial heritage and the exploitation of its natural resources during the modern period. Its protected status recognises the importance of such sites in understanding the technological and economic history of post-medieval British industry.
Rhymney Upper Furnace is a scheduled monument protected by Cadw under reference GM403. View the official record →
Rhymney Upper Furnace is a post-medieval blast furnace located in Wales, protected by Cadw under reference GM403.
Rhymney Upper Furnace dates from the post medieval/modern period, and is classified as a blast furnace. It is one of over 32,000 scheduled monuments protected across the UK.
Rhymney Upper Furnace 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 GM403.
Several scheduled monuments lie within 10 km, including Platform Houses on East Side of Gelligaer Common (6.7 km), Pant Ffos-yr-hebog Cup-Marked Stone (6.8 km), Gelligaer Common Round Cairns (7.1 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Rhymney Upper Furnace'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.
Rhymney Upper Furnace 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.