The structure at Ballaghkeeran Little sits on the western shore of a promontory that reaches into Ballaghkeeran Bay, part of Killinure Lough at the south-eastern end of Lough Ree. It only became visible at all because the water level in the lake dropped, exposing a scarp, or steep bank, along the shoreline. That accident of hydrology revealed what may be one of the more unusual survivals on the inland waterways of Ireland: the remnants of an ancient jetty, still partly intact.

The structure was first formally described in 1981. It consists of four horizontal oak planks that extend outward into the lough, still bearing sapwood, the outer layers of timber that are typically the first to decay. That the sapwood survives at all speaks to how thoroughly the waterlogged environment has preserved the wood, which is black in colour and clearly of considerable age. The planks are set into a grey-red marl, essentially compacted shoreline silt, and they rest within a layer roughly ten centimetres thick that contains charcoal and what is described as mixed habitation material, suggesting human activity in the vicinity over a sustained period. Approximately fifty metres to the south runs the Breensford River, and immediately to the east of the site lies what may be a promontory fort, a type of enclosure that uses natural topography, in this case a jutting landmass, as part of its defensive boundary. Whether the jetty and the possible fort were ever related in function is not known, but the proximity is suggestive of a place that once had real strategic and practical significance on the water.