Ireland’s Most Exciting Showcave

Crag Cave is formed of limestone. It is a colourful wonderland of Stalagmites and Stalactites. Discovered by cave divers in 1983, the natural, all weather tourist attraction has dramatic sound and lighting effects. It is thought to be over a million years old.

Step into 1 million years of history and wonder at Crag Cave, Ireland’s most exciting show cave! At 3.82km long, Crag Cave is the longest cave in Kerry and the seventh longest cave in the Republic offering one of the finest examples of limestone cave formation in Ireland. Etched over time into a natural wonder, this 350m show cave offers an amazing view of how a cave is formed. Come and see the incredible examples of pillars, stalactites, stalagmites, flowstones, curtains and straws that have been meticulously forming over the last 15,000 years.

Survey of the show cave section of Crag Cave. Red line highlights the tour route.

Limestone Outcrop

The tour begins at a limestone outcrop at the cave’s entrance. It is here that you will hear how this rock was formed 350 million years ago and what processes took place to form the cave. The solubility of limestone and its brick-wall-like structure will be explained which all contributes to how these spectacular cave passages have been formed.

You will learn about the prehistoric creatures that filled Ireland’s waters 200 million years before dinosaurs first began to walk the earth. If you’re lucky, you may even find a fossil of one of these ancient creatures hidden in the walls of the caves!


Divers Delight

Descend the passage way constructed in 1988 and enter into the cave of wonder. Here you will learn the exciting story of the cave’s discovery by Professor John Gunn from UCC and world renowned Welsh cave diver Martyn Farr in the early 1980s. Experience the thrill felt by Farr when he first shone his torch into the darkness and discovered the wondrous caverns, passages and cave formations for the first time.

The cave was originally entered via a 24ft flooded U-shaped passage. Mud and silt that sit on the edge of the dive pool visible in Divers Delight made visibility in the water impossible creating a very dangerous expedition for Martyn Farr. His thrill at discovering the “caverns measureless to man” in Crag Cave encouraged him to name the cavern “Divers Delight”.

The cave was developed between 1987 and 1989 by constructing a shaft (the only man made entrance) and putting in pathways, railings and lights.


The Big Stalactite

Here you will see our “Corn on the Cob” stalactite and the “soft mud” stalagmite below it. Formed by water dripping from the ceiling and depositing small amounts of calcite, the stalactite has been dated at approximately 6,000 years old. It is one of the largest stalagmites in the system measuring at over 2m long.

At this stop you will also see the oldest part of the cave which is over one million years old. This takes the form of tunnels eroding into one another over time.

The Big Chamber (Minas Tirith)

Being avid Lord of the Rings fans, the first explorers of this cave named this cavern “Minas Tirith” after the great city of Gondor in Middle Earth. This chamber was formed by three separate passages joining together and reveals the stream that runs through the cave continually eating into the rock and creating new crevices to explore.

This is still an actively forming cave system. Who knows what mysteries of the hidden depths will be revealed in tens of thousands of years’ time?



At this stop, a different type of formation is seen. This is formed by water flowing across the floors and walls of the cave and is named flowstone. Here you will see a “dead” formation (that is no longer forming) and a feature that it still actively forming.

Drapery features are seen hanging off the edge of the flowstone creating a formation with an alien appearance that at the same time has the familiarity of the stalactites.

This section of the caves highlights impurities that enter water as it flows through soil and overlying rocks and stains the formations within the cave creating unusual colours among the pure white calcite.


The Kitchen

This entertaining part of the cave allows adults and children alike to have a little fun trying to recognise some everyday items you would find in a kitchen within the cave formations! These can range from food items to glassware so make sure you keep an eye out and get creative!


Diarmuid and Gráinne

The story of Diarmuid and Gráinne has been told in many different ways, but none as exciting as our personalised rendition. In an attempt to escape the great warrior Fionn Mac Comhaill, Diarmuid and Gráinne spent a night in hiding in a cave in the Sliabh Luachra area. We believe this to be Crag Cave.

Their journey and time spent in hiding is recreated in Crag Cave in a way nowhere else can achieve. Perhaps there’s still a little bit of magic left in Castleisland…

The Cathedral

The domed ceiling in this part of the cave gave rise to the title of “The Cathedral”. This impression is enhanced by the candlestick-shaped stalagmite precariously perched on a ledge that draws visitors’ attention.

The unusual shape of the stalagmite gives visitors both an idea of the rate of growth for stalagmites and the past climate for Ireland, especially the last time Ireland had a warm, dry climate… ending about 5,000 years ago!


The Crystal Gallery

The Crystal Gallery is possibly the most spectacular section of Crag Cave. Here you will see thousands of straw stalactites delicately dropping down from a roof of pure white calcite. Being hollow in the centre, these straws are exceptionally fragile and occasionally snap off the ceiling under their own weight. In places, the cave is littered with the remains of these beautiful formations. What is startling about this chamber is the realisation that all the stalactites in the cave, even the large one near the entrance, were originally straws that became stronger to create the larger formations that are now seen.

The Michelin Guide who rated Crag Cave with 2 stars describes the beauty of the Crystal Gallery as “eliciting gasps of wonder”. This is truly a sight not to be missed.



This is one of our most famous stalagmites in the cave system. It is said to resemble the Madonna and Child. With a little bit of faith, it is possible to make out the Virgin Mary holding the Baby Jesus in her arms.

Cave survey of Crag Cave and Crag Lower Cave drawn by Catherine Gunn. Image from Bunce et al. 2009: The Caves of County Kerry

Crag Cave Timeline

Ma = Millions of years ago


At the end of the Devonian time period there is a global sea level rise. This floods Ireland and means most of it now sits under water.


During the Carboniferous, the majority of limestone in Ireland forms at the bottom of a warm, tropical sea. At this time, Ireland was south of the Equator, covered by a warm sea containing reefs and animals, many of which are now extinct. The sea was near to a large continent known as Laurussia (modern day North America, Greenland, and Europe). This rock is dated using the fossils of the shells and skeletons of sea creatures that settled on the sea floor before becoming cemented by mud to for the limestone we now see today.


Ireland is part of the Eurasian tectonic plate. During this time the African and the Eurasian plate collide causing the landscape to be uplifted and folded. This exposed the limestone on the surface where it begins to get weathered and eroded.


Crag Cave begins to form as mildly acidic rain water dissolves the limestone along weaknesses in the joints and bedding, Eventually, a sink hole opens up allowing rivers and streams to flow underground increasing the rate of cave formation.

10,000 yrs. Ago

The river continues to move deeper into the limestone as it erodes its way downwards. A system of caves and caverns has developed by this point and cave formations such as stalactites and stalagmites begin to grow. The last ice age had just ended and as the large volumes of ice begins to melt, there is an increase in the volume of water flowing through the cave.


The Geological Survey Memoir to Sheet 162 makes note of caves in the area of Castleisland. It states that there are “caves worn by water, some of which can be traversed for some distance” (Foot et al. 1859).


Jack Coleman notices and comments on “a line of unnamed holes running north and south approximately east of Crag House”.  These may have been in reference to sink holes that allowed the Ahroe stream to flow underground and form the Crag Cave system (Coleman, 1965).


While investigating water pollution in the Castleisland area, the waterworks supervisor David Keane tells Prof. John Gunn about a cave near Crag House that he had explored as a child. Some minor exploration takes place and 3 entrances are discovered, 2 of which are blocked up. John Gunn returns to Castleisland with some students to explore the area further and map it and uncover a 300m cave that ends in a sump (a flooded passage). The cave becomes known as Crag Lower Cave.


John Gunn publishes “Crag Cave, County Kerry” through the Irish Naturalists’ Journal.


World renowned cave diver Martyn Farr visits Castleisland from Wales to explore the sump at the end of Crag Lower Cave. He discovers Crag Upper Cave and names the cavern “Divers Delight”. He is followed through by John Cooper and the two explore the cave. The surveyed 1,670m over two days and christen many of the newly found passages with names from JRR Tolken’s Lord of the Rings.


A further 1,179m of passage is surveyed. The cave measured approximately 3.82km making it the 10thlongest cave on the island of Ireland.


Development of Crag Cave into a show cave begins. Brian Judd, a cave engineer, begins constructing a stairwell that will lead from the surface down into Divers Delight Chamber. Theatrical designer Michael Scott designed a special lighting system to “create a uniquely evocative visual and aural landscape”.


Crag Cave opens its doors to the public for the first time on 20th of May.


An Taoiseach Charles Haughey officially opens Crag Cave.


Crag Cave welcomes its 50,000th visitor.


A research project is initiated in Crag Cave funded by the EU Environment Programme. The aim of the project is to reconstruct the climate conditions for the past 10,000 years. The project involves 8 scientists from 5 European countries and runs until 1996.


Crag Cave has welcomed 100,000 visitors.


The Crag Cave Café is extended. It now provides more seating for visitors and a larger menu.


Crag Cave has had 500,000 visitors since it first opened ten years previous.


Crag Cave joins the International Show Cave Association.


Crag Cave becomes part of the Association of Irish and British Show Caves.


Crag Cave reaches a landmark achievement with 1 million visitors who have witnesses the spectacular beauty of the show cave.

The award winning Santa’s Winter Wonderland is first launched at Crag Cave.


Crazy Cave adventure Centre is opened to the public and becomes Kerry’s No 1 House of Fun while complimenting the attraction of the Cave itself.


1.25 million people have now visited Crag Cave.


The Garden Restaurant is opened complimented by a bright, spacious, new conservatory dining area.


The outdoor areas beside the cave are extended with a patio area and a climbing wall for children.


1.5 million visitors and growing!