Aillwee Cave (Irish: Pluaiseanna an Aill Bhuí) is the most famous of the many thousands of ancient caves beneath the karst-landscape of the Burren in northwest County Clare, Ireland. The name Aillwee is derived from the Irish Aill Bhuí which means yellow cliff.
The cave system consists of over a kilometer of passages leading into the heart of the mountain. Its features include an underground river and a waterfall as well as some large stalactites and stalagmites. The remains of bears can also be seen inside the caves. It was discovered in the early 20th century, when a farmer followed his dog who was chasing a rabbit. The farmer did not explore very far into the caves, and did not tell anyone of the find for nearly 40 years. He revealed his secret in the 1970s, and two years later, after the proper safety precautions were taken, it was officially opened to the public. The caves are now open daily from 9:30am throughout the year.
The caves appear in the Father Ted episode "The Mainland" under the name "The Very Dark Caves".
Inside Aillwee Cave.
Aillwee Cave official website: http://www.aillweecave.ie/