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Mynydd y Garn is a prehistoric round cairn situated on the Dinantian limestone landscape of Wales. The monument consists of a circular mound of stacked stones, typical of Bronze Age burial practices in upland Britain. Built directly upon bedrock of limestone, sandstone and argillaceous rocks formed during the Mississippian period, the cairn would have been constructed from locally available stone cleared from the surrounding moorland. Such elevated, exposed locations were commonly chosen for ceremonial burial monuments, offering prominence in the landscape and long views across the surrounding terrain.
The cairn represents a significant investment of communal labour, with stones gathered and carefully piled to create a durable funerary structure that has endured for over three millennia. The monument's preservation on the open hillside has left it vulnerable to weathering and stone robbing, yet its core structure remains archaeologically valuable. The limestone bedrock and surrounding geology would have been well known to the Bronze Age communities who built and used this site for burial and ritual purposes.
Mynydd y Garn is protected as a scheduled monument under Cadw reference BR345, recognising its importance to Wales's archaeological heritage. The cairn contributes to the wider pattern of prehistoric ceremonial sites distributed across the Welsh uplands, marking territories, ancestral connections and ritual landscapes of ancient communities.
Mynydd y Garn round cairn is a scheduled monument protected by Cadw under reference BR345. View the official record →
Mynydd y Garn is a prehistoric round cairn situated on the Dinantian limestone landscape of Wales. It is designated a Scheduled Ancient Monument by Cadw under reference BR345.
Mynydd y Garn round cairn dates from the prehistoric period, and is classified as a round cairn. It is one of over 32,000 scheduled monuments protected across the UK.
Mynydd y Garn round cairn 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 BR345.
Several scheduled monuments lie within 10 km, including Ring Cairn and Round Cairn on Southern Side of Mynydd-y-Glog (6 km), Glynneath Gunpowder Works (7 km), Dinas Silica Mine (7 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Mynydd y Garn round cairn'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.
Mynydd y Garn round cairn stands on Dinantian Rocks (Undifferentiated), bedrock that formed in the Mississippian. The rock here is limestone with subordinate sandstone and argillaceous rocks.