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Allt Hengeraint Pillbox is a post-medieval defensive structure situated in Wales and protected by Cadw under reference CD247. Built during the Second World War as part of Britain's anti-invasion defences, this small concrete fortification exemplifies the rapid deployment of pillbox networks across the British Isles in the early 1940s. The structure sits upon bedrock of Llandovery age, comprising interbedded sandstone and conglomerate deposits that formed during the Ordovician period over 450 million years ago.
The underlying geology of sandstone and conglomerate provided a moderately stable foundation for the pillbox's construction, though such Palaeozoic rocks in Wales are often heavily weathered and fractured. The site's position reflects strategic military planning during a period when German invasion was perceived as an immediate threat following the fall of France. Hundreds of pillboxes were hastily constructed across Britain to create defensive lines, particularly in vulnerable coastal and border regions.
Today, the pillbox remains a tangible remnant of Second World War anxieties and the mobilisation of the landscape for military purposes. Protected as a monument, it contributes to our understanding of wartime Britain and the engineering responses to existential threat. The structure's survival on the Llandovery bedrock demonstrates the durability of concrete construction even in areas subject to considerable geological and climatic weathering.
Allt Hengeraint Pillbox is a scheduled monument protected by Cadw under reference CD247. View the official record →
Allt Hengeraint Pillbox is a post-medieval defensive structure situated in Wales and protected by Cadw under reference CD247.
Allt Hengeraint Pillbox dates from the post medieval/modern period, and is classified as a pillbox. It is one of over 32,000 scheduled monuments protected across the UK.
Allt Hengeraint Pillbox 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 CD247.
Several scheduled monuments lie within 10 km, including Castell Allt Craig-Arth (3.1 km), Fish traps on Beach SW of Aberarth (3.2 km), Defended Enclosure 130m ENE of Capel Ciliau Aeron (3.4 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Allt Hengeraint Pillbox'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.
Allt Hengeraint Pillbox stands on Llandovery Rocks (Undifferentiated), bedrock that formed in the Llandovery. The rock here is sandstone and conglomerate, interbedded.