Overview
Dunmore Cave is small as show caves go – a quarter-mile of passages dropping about 46 m into the Castlecomer Plateau – but it holds two things bigger caves don’t: some of the most impressive calcite formations in Ireland, and a ninth-century Viking story written into the rock. Access is by guided tour only, down a sequence of lit chambers linked by stone steps. The centrepiece, and the one thing to make sure you see, is the Market Cross, a calcite column rising more than 5.8 m that looks uncannily like a medieval high cross.
A contested Viking past
The cave’s history is as layered as its limestone. It first appears in the 9th-century Triads of Ireland, which list it among the three darkest places in the country. The grimmer story comes from the annals: in AD 928 a Viking force is said to have killed around a thousand people sheltering inside, many of them suffocating in the deepest chambers.
How much of that is true is unsettled. Archaeologists have recovered human remains from the cave, from infants to adults, but the case for a single massacre is thinner than the story suggests, and some now read the site as a place of refuge and burial rather than a battlefield. What is not in doubt is the treasure. In 1999 a hoard of 43 silver and bronze items, dated to around 970, was found in the cave – the kind of cache someone buries meaning to come back for.
The site was designated a National Monument in 1944 and opened to the public in 1967. After a spell of closure for research in the early 2000s, it reopened with modern lighting, safe walkways and a visitor centre that lays out both the geology and the disputed history.
Geology and the underground landscape
Dunmore Cave is a solutional cave, dissolved out of Carboniferous limestone over a very long time as groundwater worked along the rock’s joints. Inside it stays cold and damp year-round, the conditions that let calcite build slowly into stalactites, stalagmites, sweeping flowstones and thin, curtain-like draperies.
The cave also supports a small resident bat colony, and look closely and you can pick out the odd bat skeleton fused into the limestone of the walls. The constant drip of water sets the pace of the tour, and of the cave itself.
Planning your visit
- Guided access only – Every visitor joins a guided tour, capped at 50 people. Walk-ins are taken on a first-come basis, but during school holidays and summer weekends it is worth booking ahead by emailing dunmorecaves@opw.ie.
- Admission – Adult €5.00, Group/Senior €4.00, Child/Student €3.00, Family €13.00 (two adults and up to three children). The price covers the tour and the visitor centre.
- What to wear – The cave is cold and damp whatever the weather outside, and the floor can be slick. Sturdy, non-slip shoes are essential; bring a jacket or jumper even in July.
- Steps and mobility – The route runs to roughly 700 steps over uneven ground and is not wheelchair accessible. Anyone with a heart condition or serious mobility issue should think twice.
- Facilities – Free car park, bicycle parking, toilets and a visitor centre with an exhibition and audio-visual show. There is no café on site, so bring a flask if you want something hot after the climb back up.
- Combining your trip – Dunmore Cave sits just north of Kilkenny city. Kilkenny Castle is about 9 km south, and Jenkinstown has forest walks and a walled garden ten minutes away. The Black Abbey in the city and the Cistercian ruins at Jerpoint Abbey make easy add-ons.
Book ahead in summer and at weekends, and allow about an hour for the tour.