The original Viking settlement occupied a triangular wedge of land between the River Suir and the lesser stream of John's River, with Reginald's Tower at its apex. The streets are still narrow inside this Viking Triangle, the medieval architecture still legible, and the civic spaces still oriented to the old plan. In April 2003, archaeologists discovered an even older Viking site at Woodstown near the city -- a fifth-century Iron Age and ninth-century Viking settlement that appears to predate every other Viking town in Ireland. In the 15th century the city expanded westward with an outer wall, and today Waterford retains more of its medieval walls than any Irish city except Derry. The historian Mark Girouard once called the mile-long Waterford Quay 'the noblest quay in Europe', and a thousand years of trade up the Suir is part of the reason.

Two things made Waterford famous beyond Ireland. The first was crystal: George and William Penrose started the Waterford Glassworks in 1783, and over two and a half centuries the name became shorthand for elegance, from the chandeliers in Westminster Abbey to the New Year's Eve ball that drops in Times Square. The second was the siege. In 1649 Oliver Cromwell laid siege to Catholic Waterford and failed, beaten back by an Irish commander named Richard Farrell who had learned siege warfare in the Spanish army in Flanders. The city did not fall until August 1650, after bubonic plague broke out inside the walls and Cromwell's son-in-law Henry Ireton brought up his siege guns. Waterford was the last Irish Catholic stronghold in the east of Ireland to fall.

Modern Waterford spreads across several distinct quarters. John Roberts Square, locally known as Red Square for its paving, was named after the Waterford-born architect who designed much of the Georgian city. The Mall is a Georgian thoroughfare laid out by the Wide Streets Commission and contains some of the finest 18th-century architecture in the country. Ballybricken, just outside the walls to the west, is thought to have been the city's Irishtown -- the settlement that grew up to house Vikings and Irish expelled from the medieval core after the Norman invasion. The Apple Market, once a literal apple market, is now Waterford's nightlife quarter. And T. & H. Doolan's pub on George's Street has been licensed since the 18th century but is believed to be closer to 500 years old; one of the original city walls runs through its lounge.

Waterford is the main city of Ireland's South-East Region, with a 2022 population of 60,079. Its port is Ireland's closest deep-water harbour to mainland Europe and handles around 12% of the country's external trade by value. The Waterford Greenway, Ireland's longest, runs out of the city for 46 km through Mount Congreve, Kilmeaden, and Kilmacthomas to Dungarvan, mostly along an old railway line. South East Technological University, formed in 2022 by the merger of Waterford Institute of Technology and IT Carlow, has its main campus here. Above the Suir the cable-stayed River Suir Bridge spans 230 metres -- the longest single bridge span in Ireland -- carrying the N25 toward Cork. Below, the river still flows past quays where Viking longships once tied up, where Cromwell's army could not get its siege guns, and where the crystal that ends up in Times Square is still loaded for export.