This hook-shaped fish trap is depicted on historic OS mapping (1898-1947), and is very similar in appearance to NPRN 301206 (Ogwyn Weir Fish Trap), situated 700m to the east. The fish trap is consructed of a single row of round wooden posts measuring approximately 10cm diameter and 60cm height. The west arm extends some 1100m in total, beginning some 50m inland and gently curving in a north-westerly direction for approximately 350m, at which point it runs north until it reaches the 'V' shaped hook. The east arm begins here and runs south-east for approximately 260m, terminating with a very small arm which turns 90 degrees inwards and extends some 20m. Further features are visible on an historic (1899) Admiralty chart, and probably represent different phasing. A third arm extends from a point some 440m west of the west arm's shoreward end (at the high water mark) and terminates slightly north of the apex or 'V'. At this point a fourth arm runs parallel to the hook of the east arm, forming a second hook some 50m south of the first one. A fifth arm extends from the top of the third arm, forming a third hook which also runs parallel to the east arm, some 50m further north. Historic mapping (1885-1947) depicts a footpath, whose purpose appears to have been to service NPRN 301206 (Ogwyn Weir Fish Trap). The footpath extends from what is depicted as a muscle farm on modern OS mapping, and crosses the south arm, at which point historic mapping depicts a gap or gate in the fish trap arm. The fish trap is thought not to have been used within living memory.

Sources include:
Gwynedd Archaeological Trust, 2012, Historic environment Record
Ordnance Survey, 2012, Mastermap
Ordnance Survey, 1885-8, 1st edition 25" Landmark
Ordnance Survey, 1898-1900, 2nd edition 25" Landmark
Ordnance Survey, 1912-20, 3rd edition 25" Landmark
Ordnance Survey, 1939-47, 4th edition 25" Landmark
Chart 1174-A4 date 1839

Maritime Officer, RCAHMW, January 2011.