This 'P' shaped fish trap consists of cobbles measuring 20-30cm across reinforced by wooden posts measuring 18-25cm diameter. The main section extends from near the high water mark, and is orientated east-west. It consists of a bank extending to 50cm height, whose spread is approximately 12m width. The arm extends 260m, with its apex at the low water mark, orientated northeast. There is no evidence of a cod-end or sluice at this point. The arm then extends south and runs parallel to the shoreline for some 170m, before curving inland (forming the horn of the 'P') and running some 86m in a northwesterly direction. The arm appears to peter out some 90m before it would converge with the main arm, although a survey shows it changing orientation at this point, to run east-west (back towards the shore) parallel to the main arm. This change in orientation is not apparent from modern AP coverage, but appears to be depicted on the 3rd edition (1939-49) OS map. The horn of the 'P' retains a pool of water at low tide, which is shown on the modern OS map.

Event and Historical Information:
It is probable that this fish trap formed part of the fisheries at Rhos Fynnach referred to in a 1230 charter as part of property later transferred to the cistercian Abbey of Aberconwy. After its dissolution, Aberconwy's property reverted to the Crown. Along with NPRN 303159, the Rhos Fynach weir (or Royal Fishing Weir) it is almost certainly one of the two weirs referred to at this location in a document of 1767.

Sources include:
Ordnance Survey, 2012, Mastermap
Ordnance Survey, 1911-18, 3rd edition 25" Landmark
Turner, R, The Coastal Archaeology of Wales, 2002 'Fish Weirs and fish traps' 95-109

Maritime Officer, RCAHMW, January 2011.