© Mapbox · © OpenStreetMap contributors · Boundary data © Cadw
Twyn-y-Gaer is a medieval pillow mound located in Wales and protected as a scheduled ancient monument by Cadw under reference BR043. Pillow mounds are artificial earthworks constructed during the medieval period, typically built to improve drainage and create suitable habitat for rabbits and other small game animals in enclosed warrens. The monument sits on bedrock of Lower Devonian rocks, a geological sequence of mudstone, siltstone and sandstone formed during the Early Devonian period over 400 million years ago. This substantial foundation would have provided a stable base for the earthwork's construction and subsequent use.
The mound's survival reflects both the durability of its physical form and the protective value placed on medieval hunting resources. Such structures were labour-intensive undertakings, indicating significant manorial investment in game management and food production. The Devonian bedrock beneath the site, typical of much of Wales, would have presented particular challenges for drainage work, making the construction of purpose-built pillow mounds particularly important for creating the well-drained conditions necessary for successful rabbit populations.
Today Twyn-y-Gaer stands as evidence of medieval land management practices and the economic importance of small game to rural communities.
Twyn-y-Gaer is a scheduled monument protected by Cadw under reference BR043. View the official record →
Twyn-y-Gaer is a medieval pillow mound located in Wales and protected as a scheduled ancient monument by Cadw under reference BR043.
Twyn-y-Gaer dates from the medieval period, and is classified as a pillow mound. It is one of over 32,000 scheduled monuments protected across the UK.
Twyn-y-Gaer 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 BR043.
Several scheduled monuments lie within 10 km, including Y Gyrn hut platform (N) (5.3 km), Y Gyrn longhuts (5.4 km), Y Gyrn hut platforms (5.4 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Twyn-y-Gaer'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.
Twyn-y-Gaer stands on Lower Devonian Rocks (Undifferentiated), bedrock that formed in the Early Devonian. The rock here is mudstone, siltstone and sandstone.