Most visitors to Bunratty associate the area with its castle and folk park, yet out in the tidal channel, largely invisible and rarely discussed, are the waterlogged bones of a structure that may have been catching fish since the medieval period.

The remains were documented in February 1997 and described by archaeologist Aidan O'Sullivan as comprising a post-and-wattle fence, a horizontal post-and-wattle panel, and a series of vertical posts with horizontal branches, all exposed in the estuarine clays over an area measuring roughly ten metres along a northeast-to-southwest axis and one metre wide. Post-and-wattle construction, in which upright stakes are woven through with flexible branches or rods, is one of the oldest building techniques in Ireland, and its use here reflects how the same methods employed in walls and enclosures on land were adapted for the very different demands of tidal fishing. A fish weir of this type would have worked by channelling fish into a confined space as the tide receded, allowing them to be collected when the water fell away. The Bunratty example sits within a tradition of intertidal fish traps well attested along Irish estuaries, though its precise date remains uncertain.