| Glynrhonwy | |
| Width: | 250px |
| Pushpin Map: | Wales Gwynedd |
| Pushpin Mapsize: | 250px |
| Pushpin Map Alt: | Map of Gwynedd showing the position of the quarry |
| Pushpin Map Caption: | Location in Gwynedd |
| Coordinates: | |
| Place: | near Llanberis |
| Subdivision Type: | County |
| State/Province: | Carnarvonshire (now Gwynedd) |
| Country: | Wales, UK |
| Products: | Slate |
| Type: | Quarry |
| Opening Year: | early 1700s |
The Glynrhonwy quarries (also known as the Glyn-Rhonwy quarries) were two adjacent quarries in the Glynrhonwy area, north-west of Llanberis, in Carnarvonshire (now Gwynedd), Wales.
They were:
The quarries operated internal railways of gauge and were served by Glynrhonwy Siding off the LNWR's Caernarfon to Llanberis branch.[1]
Lower Glynrhonwy was acquired by the Air Ministry in 1939 for munitions storage. It occupied the site until 1961.[2] During the Second World War the site generated two extra trains per day on some occasions. The railway siding was taken out of use on 18 December 1956.
A 100 MW pumped storage project, marketed as a "quarry battery", received approval in 2017 and as at 2019 had reached the "detailed engineering design" stage.[3] [4]