The name Burren comes from the Irish word boireann. It means “a place of rocks.”

And that’s what the Burren is, a vast limestone deposit.  The Burren is an enormous glaciated karst in northwestern County Clare, Ireland.  Depending on whose measurements you use, the Burren is between 97 and 500 square miles. Either way, that is vast.

The Burren is a huge porous limestone deposit. The limestone pavements are separated by clints, deep fissures. Water drains into these cracks and creates caves, forming an extensive network. More than 31 miles have been mapped.

More about the Burren & Ireland >

Cave in the Burren - The Underground Burren, Ireland – The Underground World of Caves
Cave in the Burren
Photo by Sometimes Incoherent

The limestone of the Burren is honeycombed with caves.

Doolin Cave in the Burren, Ireland - The Underground Burren, Ireland – The Underground World of Caves
Poll an Ionain, Doolin Cave in the Burren, Ireland
Photo by Robert Linsdell

Poll an Ionain is a limestone cave near Doolin in County Clare.

The Great Stalactite in Doolin Cave in the Burren, Ireland - The Underground Burren, Ireland – The Underground World of Caves
The Great Stalactite in Doolin Cave in the Burren
Photo by Rene Scaunce

The longest free-hanging stalactite in Europe can be seen there. Depending on what you read, it may be over 30 feet long.

Caher River in flood at Kyber Pass in the Burren The Caher is the only permanent overground stream in the Burren. It is usually just a trickle. At the Kyber Pass it cuts through a moraine - The Underground Burren, Ireland – The Underground World of Caves
Caher River in flood at Kyber Pass in the Burren
The Caher is the only permanent overground stream in the Burren. It is usually just a trickle. At the Kyber Pass it cuts through a moraine.
Photo by Dr Charles Nelson

These caves are still active. Streams, rivers, even waterfalls run under the Burren. The Caher River runs mostly under the Burren and flows into the sea at Fanore. Aillwee Cave may be the oldest cave in the Burren.

Formations in Aillwee Cave in the Burren - The Underground Burren, Ireland – The Underground World of Caves
Formations in Aillwee Cave in the Burren
Photo by Ardfern

Aillwee Cave

Aillwee Cave was discovered in 1944 by a local farmer. He didn’t tell anyone about the caves until 1973.

Aillwee Cave in Ireland - The Underground Burren, Ireland – The Underground World of Caves
Caver in Aillwee Cave in Ireland
Photo by Nils E.

Cavers found a much older cave than others in the area. They have explored up to 3,379 feet.

Formations in Aillwee Cave in the Burren - The Underground Burren, Ireland – The Underground World of Caves
Formations in Aillwee Cave in the Burren
Photo by Ardfern

As soon as they saw Aillwee Cave, they could see the potential for a show cave. By 1976, it had opened to the public. The public tour has 980 feet of cave passage, nearly a third of the cave. The tour includes extraordinary stalactites, stalagmites, and other rock formations.

Brown Bear bones in Aillwee Cave in the Burren - The Underground Burren, Ireland – The Underground World of Caves
Brown Bear bones in Aillwee Cave in the Burren
Photo by Topika26
Brown Bear bones in Aillwee Cave in the Burren - The Underground Burren, Ireland – The Underground World of Caves
Brown Bear bones in Aillwee Cave in the Burren
Photo by Topika26

Cave explorers also found traces of brown bears, which has been extinct in Ireland for more than a thousand years. Brown bears hibernated in Aillwee Cave, where the temperature stays at 50 degrees Fahrenheit all year.

There is also a café and gift shop.

Formations in Aillwee Cave in the Burren - The Underground Burren, Ireland – The Underground World of Caves
Formations in Aillwee Cave in the Burren
Photo by Ardfern
Stalactites in Aillwee Cave - The Underground Burren, Ireland – The Underground World of Caves
Stalactites in Aillwee Cave
Photo by Charles W Glynn
Waterfall in Aillwee Cave - The Underground Burren, Ireland – The Underground World of Caves
Waterfall in Aillwee Cave
Photo by Marvin Vells
Waterfall in Aillwee Cave - The Underground Burren, Ireland – The Underground World of Caves
Waterfall in Aillwee Cave
Photo by Marvin Vells
Aillwee Cave in Ireland - The Underground Burren, Ireland – The Underground World of Caves
Aillwee Cave in Ireland
Photo by Nils E.
Aillwee Cave in Ireland - The Underground Burren, Ireland – The Underground World of Caves
Aillwee Cave in Ireland
Photo by Nils E.
Aillwee Cave in Ireland - The Underground Burren, Ireland – The Underground World of Caves
Aillwee Cave in Ireland
Photo by Nils E.
Aillwee Cave in Ireland - The Underground Burren, Ireland – The Underground World of Caves
Aillwee Cave in Ireland
Photo by Nils E.

The Underground Burren, Ireland