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:
Upper Glynrhonwy quarry, known locally as "Glyn Ganol" or "Middle Glyn", which operated from 1861 to 1930,[1] and
Lower Glynrhonwy quarry, known locally as "Captain Taylor's Quarry", which operated from the early 1700s to 25 January 1930.[2]
Lower Glynrhonwy was acquired by the Air Ministry in 1939 for munitions storage. It occupied the site until 1961.[5] During the Second World War the site generated two extra trains per day on some occasions.[6] The railway siding was taken out of use on 18 December 1956.[7]
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.[8][9]
Mitchell, Vic; Smith, Keith (2010). Bangor to Portmadoc: Including Three Llanberis Lines. Country Railway Routes. Midhurst: Middleton Press. ISBN978-1-906008-72-7.