Beneath the streets of Dungarvan, Co. Waterford, there is a medieval town that nobody walks through any more. The walls that once enclosed a roughly square area of approximately 250 metres by 230 metres, running from the seafront down to Jacknell Street and west to St Augustine Street, no longer survive above ground level. Excavations at six points along their line have confirmed where they stood and revealed evidence of a fosse, the defensive ditch that would have reinforced them, but the walls themselves have been absorbed entirely into the fabric of a living town. The stratigraphy inside the enclosed area, the layered soil that archaeologists read like a slow record of occupation, was largely robbed out for clay, leaving the medieval town present but largely illegible underfoot.

Dungarvan's origins are older and more contested than its current appearance suggests. It may have begun as a Viking settlement; references to Ostmen, the Norse-Irish communities who persisted in Irish ports long after the main period of Viking activity, appear in records as late as 1250. By 1175 it had become a Royal town, and construction of the castle had begun by 1215. The Fitzgeralds, Earls of Desmond, held custody of it from 1260, though the town's ownership was repeatedly disputed. In 1463 a new grant was made to the Earl of Desmond, and the customs from a newly established daily market were directed towards repairing or possibly building the town walls. The 16th century brought further conflict: a dispute between the Earl of Desmond and Piers Butler, Earl of Ossory, ended in 1535 when James Butler and the Lord Deputy besieged and took the town. Crown rule followed from 1543. Sir Richard Boyle, Earl of Cork, purchased the town in 1618, seven years after it received a Charter of Incorporation from James I making it a parliamentary borough. The 17th century brought more violence still; the town changed hands between Confederate and Crown forces in 1642 and again in 1645, before Cromwell's forces besieged and captured it in 1649. Across the Colligan estuary in the suburb of Abbeyside, the remains of an Augustinian abbey and the site of a tower house survive as quieter markers of this layered past, while about 1.2 kilometres west of the castle, a motte, the raised earthen mound at the centre of an early Norman fortification, survives on Gallows Hill. The late 17th-century tholsel, a civic building combining courthouse and exchange functions, stands on the site of the medieval market-house, one of several places in the town where later structures have quietly replaced earlier ones without entirely erasing them.