Abbeyside lies on the east bank of the Colligan River, where it widens into Dungarvan Harbour and meets the Atlantic. The name means Dún na Mainistreach in Irish - the fort of the monastery - and refers to the Augustinian abbey that once stood here. A causeway and bridge connect Abbeyside to Dungarvan town; from the quayside you can watch the tide pull out and turn the harbour into mudflats where oystercatchers work the seagrass at low water. The Comeragh and Knockmealdown mountains rise away inland to the north and west, and the coastline runs east toward Tramore and Waterford City. The 1998 Tour de France passed through here on its Stage 2 leg out of Ireland - one of those bright summer days when the village briefly stopped being quiet.

For more than three centuries the silhouette over Abbeyside belonged to MacGrath's Castle, a six-storey tower house built by the MacGrath family and labelled MacCragh's Castle in the Civil Survey of 1654. It stood near the abbey on Friar's Walk, overlooking the harbour. Visitors in the mid-18th century described it as still in a good state of preservation; even by the early 20th century the upper storeys were intact. Then, one morning in January 1916, the whole tower simply collapsed. Fragments of the walls lingered through the next decades but were eventually cleared, and today nothing of the castle remains above ground. The village memory still places it, though. Old residents will point at empty grass and tell you exactly where the doorway stood.

Ernest Thomas Sinton Walton was born in Abbeyside on 6 October 1903, the son of a Methodist minister. He went on through Methodist College Belfast and Trinity College Dublin to Cambridge, where in 1932 he and John Cockcroft built the high-voltage particle accelerator that bombarded lithium nuclei with protons and produced helium - the first artificial splitting of an atomic nucleus. The result confirmed Einstein's mass-energy equivalence by direct experiment and gave the world the practical beginnings of nuclear physics. In 1951, Walton and Cockcroft shared the Nobel Prize for the work. Walton came home to teach at Trinity for the rest of his career and is still the only Irish-born Nobel laureate in physics. In 1989 he returned to Abbeyside in person to dedicate the Walton Causeway Park, which still bears his name.

Abbeyside has produced more than physicists. Louis Claude Purser, born on 28 September 1854, became one of the great classical scholars of his generation, professor of Latin at Trinity College Dublin and editor of the standard scholarly edition of Cicero's letters. His older sister Sarah Purser, raised in the same household, became one of Ireland's most accomplished portrait painters; she made her living from commissions when very few Irishwomen of her time made any independent living at all, and she was the first woman elected to full membership of the Royal Hibernian Academy. Sarah Purser also founded An Túr Gloine, the cooperative that produced much of Ireland's revival stained glass. Her portraits of Maud Gonne, Roger Casement, and W. B. Yeats now hang in the National Gallery of Ireland.

Modern Abbeyside is a residential part of Greater Dungarvan with one foot still in the village. The local Abbeyside/Ballinacourty GAA club fields senior teams in both hurling and Gaelic football, the two codes that dominate any Waterford parish worth its salt. Abbeyside AFC plays soccer at Division 1B level; the club's high-water mark came in 2011 when it won the division. The Augustinian church still stands at the heart of the townland, the harbour still empties twice a day, and the Comeraghs still close the horizon to the north. The castle is long gone. The Nobel laureate's plaque is small. But the bridge across the Colligan carries Walton's name, and that is no small thing for a village of this size.