Yet that is precisely what is happening. The town's road pattern is not the product of Georgian planning or Victorian improvement; it is, in large part, the fossilised outline of one of the earliest and best-preserved ecclesiastical enclosures in the county.

Early Irish monasteries were typically organised within a series of concentric enclosures, with an innermost sacred precinct surrounded by progressively less sacred zones for farming, housing, and craft work. At Lusk, both the inner enclosure, measuring roughly 110 by 100 metres, and a middle enclosure of approximately 250 by 220 metres can still be traced, not in earthworks, but in the alignment of Main Street, the northern portion of Dublin Road, Church Road, and Church Street. This was first recognised by the historical geographer F.H.A. Aalen in 1992. The outer enclosure, the largest of the three, was more elusive, but archaeological test excavations, carried out under licence in the early 2000s, located part of it beneath what is now the open green space of the Chapel Farm housing estate. Further evidence emerged during road-widening works along Church Road, where deposits associated with the outer boundary were radiocarbon dated to the early fifth through sixth century AD, placing the foundation of this site in the centuries immediately following the arrival of Christianity in Ireland.

For a visitor, the experience is one of reading rather than viewing. There is no earthen bank to walk along, no dramatic ruin announcing the site's age. Instead, the pleasure is in standing on Church Road or Main Street and understanding that the gentle curve of the road beneath your feet was already old when the Vikings arrived. The open green at Chapel Farm, where part of the outer enclosure was identified and then preserved rather than built over, is worth a brief stop. Lusk's medieval round tower, incorporated into a later church that is now a heritage centre, serves as the most visible landmark and a useful starting point for orienting yourself within the concentric layout that, once you know to look for it, becomes surprisingly legible in the modern streetscape.