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.

Crag Cave in Castleisland, Co. Kerry is the tenth longest cave system on the island of Ireland, with a total surveyed length of 3.82Km (12,532 feet ). The existence of the cave was known locally for many years, but only discovered by the cavers in the 1980’s. Exploration and survey took place between 1981 and 1984. The development of the present show-cave was undertaken from 1987 to 1989 by a local family with the assistance of speleologists and caving engineers. 350 meters of show-cave were opened to the public in May 1989.

At the bosom of the Glannaruddery mountains, nestling near Castleisland town in Co. Kerry, nature has fashioned her story. Wild with imagination, but with the patience of an angel, nature has orchestrated a majestic and fairy world in these dark and silent depths. Millions of years of stone masonry has culminated in Crag Cave.

Celestial caverns , where rivers once danced out their excitement, boldly stand guard over Crag’s heirless fortune. Majestic arcades run off into the deep, carrying their secret. Immense dark passages and an army of stone-chiseled forms peep out from the cave’s belly. Elevated vaults parade nature’s handiwork, where water and stone have moulded their own story.


The Geological Survey of 1859 had acknowledged the existence in the Castleisland district of ‘caves worn by water, some of which can be traversed for some distance’. It was only in 1981, however, that any positive moves were made towards the proper exploration of these caves. During the course of an investigation into water pollution in the Castleisland area, Mr. David Keane (Waterworks supervisor) informed Professor John Gunn of U.C.C. that he had explored a cave near Crag House in his youth. John Gunn and Bridget Scanlon checked out the Crag area and discovered three entrances to this particular cave. The cave itself consisted of two main sub-parrallel passages running in a north/south direction. It culminated in a complex boulder choke, at the foot of which was a sump pool.

The lower level of this cave contains the present stream, while the upper is an old abandoned streamway. A survey carried out in 1981 went north of the entrance, Poll na Gollum, near Crag House. Following the course of the underground Crag stream the passage made its way through the Hall of Moira chamber, through the Cirith Ungol passage to the end of this section and the Green Lake. It returned through Balrog’s Bathtub to the entrance.

After much persuasion on the part of the John Gunn, cave divers examined the sump, or ‘Green Lake’, as it was now termed.

In 1983 a Welsh cave diver named Martyn Farr explored the sump and found it to be only 2 metres deep and 8 metres long. He emerged, after a short dive, into what he later described as ‘caverns measureless to man’ – Crag Cave. He was soon followed by John Cooper, and both set about exploring the new discovery. The boulder choke on the west side of the sump was eventually cleared to make it accessible to the remainder of the team. A total of 1,670 metres were surveyed over a period of two days. The team christened many of the newly-found passages and chambers with names taken from J.R.R. Tolkien’s Lord of the Rings.


Emerging through Aerobes Ecstasy into Divers Delight, the team made its way to Minas Tirith (the Big Chamber) through a well–decorated walking passage. Beyond this large passage were the Cliffs of Emyn Muil, a 6 metre slope leading into an even larger chamber 27 metres long, 15 metres wide and 9 metres high. They explored further into the Forest of Fangorn, an area of fine stalagmites, including the White Tower, a superb pillar.

They then proceeded onto the Hall of Gondor and into other complex and superb passages.

On the return trip in Easter of 1984, a further 1,178 metres (3865 feet) of passage were surveyed.

It was estimated that Crag was at least 3.5km long, but recent exploration has established a total surveyed length of 3.82km putting it firmly within the ‘ top ten’ longest caves in Ireland. Further development work between Crag Cave and Crag Lower Cave could push this towards the 4km mark.

Welcome to Ireland's most exciting showcave!