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Coed Mor Fish Weir is a post-medieval fish weir located in Wales and protected by Cadw under reference AN138. Fish weirs of this period typically represent substantial fixed installations designed to trap and harvest migratory fish species, particularly salmon and sea trout, exploiting their seasonal river movements. The structure would have functioned as a permanent or semi-permanent barrier within the watercourse, employing techniques refined over centuries of Welsh riverine exploitation.
The weir sits upon hornblende schist bedrock of Neoproterozoic age, ancient metamorphic rock formed over 540 million years ago during the Earth's most remote geological history. This hard, foliated stone would have provided a stable foundation for construction, though the river itself has likely shaped the landscape considerably since the weir's construction in the post-medieval period, between the sixteenth and eighteenth centuries.
Such installations were economically significant to their communities, providing a reliable food source and sometimes generating income through leasing rights. The survival of Coed Mor Fish Weir reflects the durability of these stone structures and their integration into the Welsh landscape, though their operation would have been subject to riparian rights and, increasingly over time, to regulation and dispute between competing users of the river's resources.
Coed Mor Fish Weir is a scheduled monument protected by Cadw under reference AN138. View the official record →
Coed Mor Fish Weir is a post-medieval fish weir located in Wales and protected by Cadw under reference AN138.
Coed Mor 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.
Coed Mor 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 AN138.
Several scheduled monuments lie within 10 km, including Hut Group Near Tan-y-Coed Pont Rhythallt (7.7 km), Pen-Isa'r-Waen Camp (7.8 km), Llys Dinorwig (8.4 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Coed Mor 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.
Coed Mor Fish Weir stands on Unnamed Metamorphic Rocks, Neoproterozoic, bedrock that formed in the Neoproterozoic. The rock here is hornblende schist.