Crag Cave is a cave in Ireland, located just outside Castleisland, County Kerry. Formed in elevated limestone rock, the system extends to 3.8 kilometres (2.4 mi) of surveyed passage, on two levels. It is the 7th-longest cave system in the Republic of Ireland, and the 10th-longest in the whole of Ireland.
Around 350 metres (1,150 ft) of the Crag Cave system was developed as a show cave by local residents Dr. Donal and Mrs Margaret Geaney, under whose land the cave was first discovered. The cave was developed between 1987 and 1989 by building a shaft (which is the only man-made entrance) and putting in pathways, railings, lights and a music system. During development, the original dry connection bypassing the Green Lake was blocked off, making the new concrete shaft the only entrance to the show cave and beyond. The show cave was opened to the public on 20th May 1989.
Crag Cave attracts thousands of visitors every year. Tourists are given a guided tour of the cave which takes a half an hour. There are many chambers in the cave, including the Cathedral and the Crystal Gallery. Many of the features in the cave have been named after locations or characters from J.R.R. Tolkien's Middle-earth. The tourist centre contains a gift-shop, coffee shop and a children's play area.