This fish trap is a Scheduled Ancient Monument. It utilises a small island some 20m from the shore, and is constructed from three dry stone walls. Wall 1 measures approximately 1m height and extends from the northern tip of the island. It then runs parallel to the shore with the wall and the island together forming a channel running parallel to the shore and measuring approximately 20-25m width and 140m length. Wall 2 measures some 70m is situated at the western end of the channel, creating a dam. Wall 3 measures approximately 80m and extends from the island's northeastern tip. Together with wall 1 it forms a funnel shape. Fish would presumably have been funnelled into the channel and prevented from escaping by the dam formed by wall 3.

Sources include:
Gwynedd Archaeological Trust, 2012, Historic Environment record
National Assembly of Wales, 2009, vertical AP

Maritime Officer, RCAHMW, January 2011.