Built sometime after 1200, possibly on the site of an earlier motte, this formidable stone tower measures 13.4 metres across and rises 15.5 metres to its rebuilt parapet. Originally known as ‘Dundory’, the tower has served many purposes throughout its long history; it was a defensive stronghold in the 13th century, later became a prison, and after 1463 was repurposed as a mint. The structure played a crucial role in defending Waterford when Perkin Warbeck, pretender to the English throne, attacked the city in 1495.

The tower’s architecture tells the story of its evolution through the centuries. The original entrance sits at first floor level on the city side, though two ground floor doorways were added later. Inside, the ground floor features four window embrasures, including one with a stirrup loop, and a mural chamber to the north. A secondary doorway with a yett (iron grille gate) on the northeast side once connected to a mid-16th century blockhouse built on the river side for additional defence. Spiral stairs on the west side wind upward through all four storeys, each level revealing different periods of construction; the upper two floors date from 16th century rebuilding work.

Archaeological excavations in 1997 uncovered ten distinct phases of activity spanning from the 12th to 20th centuries, revealing how continuously occupied and important this structure has been to Waterford’s history. Each floor contains its own architectural features that reflect medieval life: the first floor houses a fireplace and garderobe (medieval toilet), whilst the second floor boasts an external doorway that may have led to the town wall’s walkway, along with another 16th century fireplace and mural chamber. The National Monuments Section carefully conserved the tower in the 1990s, ensuring this remarkable survivor of medieval Ireland continues to dominate Waterford’s waterfront.