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Bon y Maen Standing Stone is a prehistoric standing stone located in Wales and protected by Cadw as a monument of national importance under reference GM177. The stone stands on bedrock formed from the South Wales Upper Coal Measures Formation, a sequence laid down during the Westphalian period and comprising mudstone, siltstone, sandstone, coal, ironstone and ferricrete. This geological foundation, typical of the South Wales coalfield, would have been familiar to the prehistoric communities who erected the monument.
Standing stones were commonly raised across Britain and Ireland during the Bronze Age and later prehistory, serving purposes that likely included territorial markers, ceremonial sites, or memorials to the dead. The stone's position within the local landscape would have held significance for its builders, establishing a focal point within their settlement pattern or ritual calendar.
Today the monument remains a tangible record of prehistoric activity in Wales, its survival dependent on the durability of both the stone itself and the Coal Measures bedrock that anchors it. As a protected site under Cadw's stewardship, Bon y Maen Standing Stone continues to form part of Wales's archaeological heritage, contributing to understanding of prehistoric settlement and belief systems across the region.
Bon y Maen Standing Stone is a scheduled monument protected by Cadw under reference GM177. View the official record →
Bon y Maen Standing Stone is a prehistoric standing stone located in Wales and protected by Cadw as a monument of national importance under reference GM177.
Bon y Maen Standing Stone dates from the prehistoric period, and is classified as a standing stone. It is one of over 32,000 scheduled monuments protected across the UK.
Bon y Maen Standing Stone 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 GM177.
Several scheduled monuments lie within 10 km, including Earthwork on Kilvey Hill (0.7 km), Tir-Gwyllt Second World War Barrage Balloon Site (1 km), Crymlyn Bog Second World War Barrage Balloon Site (1.1 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Bon y Maen Standing Stone'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.
Bon y Maen Standing Stone 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.