The slate quarry was first opened in 1816 by the then Knight of Kerry. The slate was used for roofing and to make benches, billiard tables, sundials and many other items. Valentia slate was exported to many countries and was used to roof the British House of Commons and the Public Records Office in London is reputed to have used 25 miles of slate for shelf construction. Valentia slate was used on the construction of the Leicester Railway Station in England and the San Salvador Railway station. The quarry was closed in 1878 but has reopened again in recent years.
The Grotto was erected in 1954 when a statue of the Blessed Virgin Mary was placed at the entrance to a cave high up on the quarry and a waterfall was created where the water cascaded down from the cave entrance to a pool at ground level. The Slate Quarry area provides magnificent views over the Iveragh Peninsula and out to the Dingle Peninsula.