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Llanddona Fish Weir is a post-medieval fish trap constructed in the tidal waters off the coast of Anglesey, Wales. The structure represents a form of maritime exploitation typical of Welsh coastal communities from the early modern period onwards, designed to capture fish as tidal movements exposed and flooded the weir. Built from stone in a characteristic linear or curved configuration, the weir would have functioned as part of the local subsistence and commercial economy. The site is recorded as a scheduled ancient monument under the Cadw register (SAM AN137), reflecting its archaeological significance as evidence of historical fishing practices and coastal resource management in Wales.
Llanddona Fish Weir is a scheduled monument protected by Cadw under reference AN137. View the official record →
Llanddona Fish Weir is a post-medieval fish trap constructed in the tidal waters off the coast of Anglesey, Wales. It is designated a Scheduled Ancient Monument by Cadw under reference AN137.
Llanddona Fish Weir dates from the post medieval period, and is classified as a fish weir. It is one of over 32,000 scheduled monuments protected across the UK.
Llanddona Fish Weir 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 AN137.
Several scheduled monuments lie within 10 km, including Beaumaris Castle (6 km), Bryn Eryr Rectangular Earthwork (6.4 km), Pen-y-Maen Standing Stone (7.3 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Llanddona Fish Weir'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.
Llanddona Fish Weir stands on Early Carboniferous limestone, bedrock that formed in the Early Carboniferous. The rock here is major:{limestone}, Minor{claystone,siltstone}.