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Byrllysg promontory fort is a prehistoric promontory fort situated in Wales and protected as a scheduled monument by Cadw under reference ME064. The site occupies a naturally defensible headland, a common location for fortified settlements from the Iron Age and earlier periods. Promontory forts were typically enclosed on three sides by steep slopes or cliffs, with only the inland approach requiring artificial fortification.
The underlying geology consists of Lower Cambrian rocks—primarily mudstone, siltstone and sandstone—deposited during the Early Cambrian period over 500 million years ago. This bedrock would have been exposed across the promontory, shaping its topography and the defensive potential of the site. The local stone types available would have been suitable for building construction, though weathering of these softer sedimentary rocks over millennia has shaped the current appearance of the landscape.
As an inland promontory fort, Byrllysg would have served defensive and settlement functions for the prehistoric communities of Wales. Such sites often controlled important routes or territory, and their elevated, defensible positions made them significant places within their landscapes. The monument remains an important record of Iron Age or earlier settlement patterns in the Welsh interior.
Byrllysg promontory fort is a scheduled monument protected by Cadw under reference ME064. View the official record →
Byrllysg promontory fort is a prehistoric promontory fort situated in Wales and protected as a scheduled monument by Cadw under reference ME064.
Byrllysg promontory fort dates from the prehistoric period, and is classified as a promontory fort - inland. It is one of over 32,000 scheduled monuments protected across the UK.
Byrllysg promontory fort 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 ME064.
Several scheduled monuments lie within 10 km, including Enclosed Hut Circle Settlement and Long huts E of Egryn Abbey (3.9 km), Settlement & Fields Systems above Egryn Abbey (4 km), Mynydd Egryn Ring Cairn (4.3 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Byrllysg promontory fort'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.
Byrllysg promontory fort stands on Lower Cambrian Rocks (Undifferentiated), bedrock that formed in the Early Cambrian. The rock here is mudstone, siltstone and sandstone.