Quarrying started in 1815–1817 on Dalkey Hill in order to supply granite for the construction of the new harbour pier at nearby Dún Laoghaire, as well as for the construction of the South Bull Wall (part of the outer defences of Dublin Harbour) and as flagstone for Dublin streets.
In the 1840s, stone from the quarry was exported to Newfoundland by Bishop Michael Fleming and used in the construction of the Basilica of St. John the Baptist in St. John's.
The quarry was connected to Dún Laoghaire by a light railway, part of whose alignment was later used to build the Dalkey Atmospheric Railway.
The remaining part of the route is now a public footpath known as The Metals, and much of the original granite paving survives.
A number of the houses on nearby Ardbrugh Road may have been originally built as quarry staff cottages, though most quarrymen originally squatted or lived in primitive tents.
Quarrying continued sporadically thereafter, finally ending in 1917.

In 1914 most of the land was added to the existing Killiney Hill Park, opening it to the public.
In 1998, the local authority which owns the land drew up proposals to turn the quarry's west valley into a caravan halting site for travellers.
The move met with opposition from local residents, climbers, and environmentalists, and the plans were eventually dropped.
 In May 2010 Dún Laoghaire/Rathdown County Council angered climbers when they removed several large boulders from the quarry, disrupting climbing routes and potentially damaging other climbing routes in the process.
Quarrying started in 1815–1817 on Dalkey Hill in order to supply granite for the construction of the new harbour pier at nearby Dún Laoghaire, as well as for the construction of the South Bull Wall (part of the outer defences of Dublin Harbour) and as flagstone for Dublin streets. In the 1840s, stone from the quarry was exported to Newfoundland by Bishop Michael Fleming and used in the construction of the Basilica of St. John the Baptist in St. John's. The quarry was connected to Dún Laoghaire by a light railway, part of whose alignment was later used to build the Dalkey Atmospheric Railway. The remaining part of the route is now a public footpath known as The Metals, and much of the original granite paving survives. A number of the houses on nearby Ardbrugh Road may have been originally built as quarry staff cottages, though most quarrymen originally squatted or lived in primitive tents. Quarrying continued sporadically thereafter, finally ending in 1917.
In 1914 most of the land was added to the existing Killiney Hill Park, opening it to the public. In 1998, the local authority which owns the land drew up proposals to turn the quarry's west valley into a caravan halting site for travellers. The move met with opposition from local residents, climbers, and environmentalists, and the plans were eventually dropped.  In May 2010 Dún Laoghaire/Rathdown County Council angered climbers when they removed several large boulders from the quarry, disrupting climbing routes and potentially damaging other climbing routes in the process.
Dalkey Quarry