This was no modest ford or stepping-stone crossing; the structure would have stretched approximately 170 metres across, built from rectangular frames set on vertical posts spaced roughly five metres apart, a considerable feat of early medieval engineering carried out across what was likely a shallow but wide expanse of water or wetland connecting Connacht to the monastery-castle complex at Clonmacnoise on the Offaly bank.

The crossing sits at the intersection of two distinct phases of medieval life along the Shannon. Dendrochronology, the science of dating timber by analysing annual growth rings, yielded dates of 786 and 804 from two of the recovered timbers, placing the earlier structure firmly in the early Christian period when Clonmacnoise was at the height of its influence as a monastic centre. A later bridge, recorded as the bridge of Curr Clwana, was built by 1158 and served to connect the castle of Clonmacnoise with the road running through Coolumber bog. The site was surveyed between 1994 and 1995 by the Irish Underwater Archaeological Research Team under the archaeological direction of C. Breen and A. O'Sullivan, who located 123 timbers in total. Six log boats were also found in the same area, suggesting a broader pattern of water-based movement and activity along this stretch of the river over several centuries.