Case Study: N25 New Ross Bypass

The N25 New Ross Bypass formed part of a major road infrastructure programme through a landscape of high archaeological potential in south-east Ireland. Pre-construction and construction-phase works required archaeology to be investigated at scale while supporting delivery of the wider scheme.

Within this broader programme, Ryleen emerged as one of the most important prehistoric sites identified. Excavation revealed the footprint of an Early Neolithic house — an exceptionally significant discovery for understanding the first farming communities in the region.

Rubicon’s work at Ryleen formed part of the wider archaeological investigations undertaken for the bypass. Across the full scheme, extensive testing and excavation were used to identify, assess and mitigate archaeological remains before construction progressed.

At Ryleen, excavation focused on careful hand investigation and recording of the structural evidence, artefacts and environmental remains associated with the settlement. The aim was not only to define the footprint of the structure, but to understand how it was built, used and dated within the early prehistoric landscape.

This detailed excavation and post-excavation work allowed the site to be interpreted as an early farmer’s dwelling with internal divisions and associated occupation evidence, supported by artefactual and radiocarbon data.

The principal discovery was a rectilinear Early Neolithic house, aligned roughly north-west to south-east, measuring approximately 8.50 m by 6.25 m and defined by a foundation trench with rounded corners and a north-western entrance.

The structure included evidence for internal organisation, with a wall formed by lateral slot trenches and central postholes dividing the building into two parts. Postholes and packing stones suggest a timber construction using split oak planks, posts and wattle, while fragments of daub-like clay indicate that parts of the building were plastered with a clay-rich mixture for insulation and weatherproofing.

Finds from the associated features included Early Neolithic pottery, lithics, a polished stone axe and cereal grains, providing strong evidence for settled early farming activity. Radiocarbon dates from charred hazelnut shell place the occupation broadly between 3710–3520 BC.

Ryleen was not an isolated discovery. The archaeological works along the N25 New Ross Bypass identified more than 35 previously undocumented sites, spanning a very long chronology and demonstrating the richness of the Lower Barrow landscape.

• Identified and excavated an Early Neolithic house of high archaeological significance at Ryleen.
• Recovered structural, artefactual and environmental evidence enabling robust interpretation of the site as an early farming settlement.
• Contributed to one of the most important recent archaeological datasets generated by an Irish road scheme.
• Helped create long-term public and research value through later publication and interpretation of the bypass discoveries.

The N25 New Ross Bypass illustrates Rubicon Archaeology’s ability to deliver archaeology within major infrastructure programmes while also extracting maximum research and public value from significant discoveries.

The wider N25 New Ross Bypass archaeology programme has since been brought together through public interpretation and formal publication, including Places for the Living, Places for the Dead, helping ensure that discoveries such as Ryleen continue to inform both research and public understanding.

This long-term legacy strengthens the value of the project beyond mitigation alone, showing how infrastructure archaeology can contribute meaningfully to national narratives of settlement, landscape and identity.