The Valentia Slate Quarry was opened in 1816 by the Knights of Kerry and was run as a commercial slate quarry for almost 100 years until it was closed by a rock fall at the mouth of the quarry in 1911. At its peak, it employed up to four hundred people and supplied slate to prestigious locations such as The house of Parliament in London, Westminster Abbey, and Westminster Cathedral. It is also claimed that there are 21 miles of shelving in the Public Record Office in London made of Valentia slate.

Slate products produced from Valentia slate included roofing slates, flooring slabs, fire-surrounds, snooker tables, sills, lintels, etc. Many houses locally would have been slated with Valentia slate and are still in use today. While the quarry has a very prestigious past there is not a huge amount to see at the quarry today. The quarry is also home to a beautiful grotto that was built into the face of the quarry.