Dunmore Cave, not far from Kilkenny town, is a series of limestone chambers formed over millions of years. It contains some of the most impressive calcite formations found in any Irish underground structure.

The cave has been known for many centuries and is first mentioned in the ninth-century Triads of Ireland, where it is referred to as one of the ‘darkest places in Ireland’. The most gruesome reference, however, comes from the Annals of the Four Masters, which tells how the Viking leader Guthfrith of Ivar massacred a thousand people there in AD 928.

Archaeological investigation has not reliably confirmed that such a massacre took place, but finds within the cave – including human remains – do indicate Viking activity.