General Workers' Union unveiled a plaque in memory of those who participated. Recent history From 1963 until 2007 the quarry was owned and operated by Alfred McAlpine. In 2007 it was purchased by Kevin Lagan (an Irish businessman who is the owner and chairman of the Lagan Group) and renamed Welsh Slate Ltd. Kevin Lagan and his son Peter (MD of Lagan Building Solutions Ltd) are now directors of Welsh Slate Ltd which also includes the Oakeley quarry in Blaenau Ffestiniog, the Cwt Y Bugail quarry and the Pen Yr Orsedd quarry. The Lagan Group was itself acquired by the Leicestershire-based Breedon Group in 2018. A part of the site no longer in use for slate extraction is the site of a new adventure tourism facility operated by Zip World. The zip line Velocity 2 flies over an abandoned and partially flooded part of the quarry. Welsh slate such as that quarried at Penrhyn was designated by the International Union of Geological Sciences as a 'Global Heritage Stone Resource' early in 2019 in recognition of its significant contribution to world architectural heritage. Railways See also Blondin (quarry equipment) – originated at Penrhyn The 2nd Baron Penrhyn – who closed the quarry in response to a strike in 1897 References External links The official website of Welsh Slate Ltd., the owners of Penrhyn quarry The quarry's entry (including much description of the site, location map, etc.) on the National Monuments Record of Wales (NMRW)'s https://coflein.org website History and photos "The Penrhyn Slate Quarry," in Saturday Magazine, No. 12, 8 September 1832, pp. 93. The Penrhyn Slate Quarries in North Wales circa 1858, in The Illustrated London News, Vol. XXXII, No. 913, Saturday, 17 April 1858, pp. 392–393. History of Bangor Blue Slates In Ireland Bethesda, Gwynedd Llandygai Open-pit mines Slate mines in Gwynedd The Slate Landscape of Northwest Wales