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Crymlyn Bog Second World War Barrage Balloon Site is a modern defensive installation located on the coal-bearing lowlands of South Wales. The site sits upon bedrock of the Upper Coal Measures Formation, comprising the mudstone, siltstone and sandstone deposits characteristic of Westphalian coal seams, alongside ironstone and ferricrete layers that underlie much of the industrial landscape of the region.
Barrage balloon sites were established across Britain during the Second World War as part of the air defence system. Tethered balloons, typically suspended at heights of several hundred feet, created an obstacle to enemy aircraft during bombing raids. The cables supporting the balloons could damage low-flying bombers, forcing them to operate at higher altitudes where anti-aircraft guns and fighters were more effective.
The Crymlyn Bog installation is designated as a scheduled monument under Cadw's protection, reference GM636, recognising its significance as evidence of wartime defence strategy. The boggy nature of the ground at this location reflects the wetland character of the Crymlyn valley, part of a landscape shaped by both natural geology and centuries of industrial activity in the South Wales coalfield.
Crymlyn Bog Second World War Barrage Balloon Site is a scheduled monument protected by Cadw under reference GM636. View the official record →
Crymlyn Bog Second World War Barrage Balloon Site is a modern defensive installation located on the coal-bearing lowlands of South Wales. It is designated a Scheduled Ancient Monument by Cadw under reference GM636.
Crymlyn Bog Second World War Barrage Balloon Site dates from the modern period, and is classified as a barrage balloon site. It is one of over 32,000 scheduled monuments protected across the UK.
Crymlyn Bog Second World War Barrage Balloon Site 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 GM636.
Several scheduled monuments lie within 10 km, including Tir-Gwyllt Second World War Barrage Balloon Site (0.7 km), Earthwork on Kilvey Hill (1.4 km), St Margaret's Chapel (1.8 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Crymlyn Bog Second World War Barrage Balloon Site'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.
Crymlyn Bog Second World War Barrage Balloon Site 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.