© Mapbox · © OpenStreetMap contributors · Boundary data © Cadw
Mounds on the Island is a medieval mound situated in Wales, protected as a scheduled monument under Cadw reference PE276. The monument occupies ground underlain by Late Carboniferous claystone bedrock, a geological foundation typical of South Wales coalfield regions. This claystone base, interspersed with siltstone, sandstone and coal seams, reflects the ancient tropical deltaic environment in which these rocks accumulated over 300 million years ago.
The mound itself represents medieval settlement or defensive activity, constructed atop this solid geological foundation. Its elevated position would have offered strategic visibility across the surrounding landscape, a common characteristic of medieval mounds that served administrative, defensive or manorial functions. The specific topography of the site, shaped by both its natural bedrock geology and artificial earthwork, contributes to its archaeological significance.
Cadw's protection of this monument recognises its importance to understanding medieval Wales. The physical remains of the mound, preserved within the modern landscape, retain evidence of medieval land use and settlement patterns. Its survival demonstrates the longevity of human settlement choices in this location, where the underlying geology and natural drainage properties of the claystone bedrock may have influenced its original selection as a site for occupation and construction.
Mounds on the Island is a scheduled monument protected by Cadw under reference PE276. View the official record →
Mounds on the Island is a medieval mound situated in Wales, protected as a scheduled monument under Cadw reference PE276.
Mounds on the Island dates from the medieval period, and is classified as a mound. It is one of over 32,000 scheduled monuments protected across the UK.
Mounds on the Island 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 PE276.
Several scheduled monuments lie within 10 km, including Landshipping House Garden Remains (3.1 km), Garden Earthworks at Coedcanlas Farm (5.8 km), Cresswell Castle 100m W of Cresswell Quay (7.1 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Mounds on the Island'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.
Mounds on the Island stands on Late Carboniferous claystone, bedrock that formed in the Late Carboniferous. The rock here is major:{claystone}, Minor{siltstone,sandstone,coal}.