A medieval roadway, entirely unrecorded until that point, emerged during excavation work carried out ahead of the construction, offering a brief and tantalising glimpse of how people once moved through this stretch of north Dublin's coastline.

The excavation, conducted under licence number 08E0376 and reported by Moriarty in 2009, uncovered a 35-metre section of a compacted metalled surface, meaning a road surface made from packed stone or gravel rather than tarmac or concrete, a common technique for medieval road construction. The surface itself was between three and 3.5 metres wide, a reasonably substantial width suggesting it was intended for regular use rather than a simple field track. On either side ran flanking ditches, each between 1.2 and 1.6 metres wide, likely serving both to drain water away from the road surface and to define its edges. The roadway runs north to south and sits approximately 200 metres west of a known medieval settlement in the area. Crucially, the excavated stretch does not represent the full extent of the road; it continued beyond the boundaries of the development site in both directions, meaning most of it remains underground and unexamined.

Because the road was uncovered as a precautionary excavation ahead of development, and because only a portion of it was exposed before construction proceeded, there is nothing to see above ground at the site today. The value of the discovery lies in what it tells us about the medieval landscape of Portmarnock rather than in any surviving visible feature. For those interested in the broader context, the nearby medieval settlement recorded as DU015-136 in the national Sites and Monuments Record gives a sense of the community this road may once have served. Local and county archaeological records, along with Moriarty's 2009 report, remain the most reliable way to explore what was found during those few weeks of digging.