The site was the largest copper mine in the world during the 18th century. Its origins date back to the Bronze Age and some areas show signs of crude tool use and fire setting. Subsequently the Romans also mined the site, but when they left there was a long period of inactivity.
The value of the site was rediscovered in the 1767 when a major ore deposit was found. Initially worked as shallow open-pits via adits and footways, pursuit of the ore ended up with workings up to 300m deep below the surface. During the 1780s the miners were producing over 4000 tons of copper ore per year. The site has reserves of copper, lead, silver and gold.
The early 1800s saw a drop in production - due to reduced demand before further increase later in the 19th century.The mine effectively ceased operating about 1904 - it is estimated 3.5 million tons of ore were extracted between 1768-1904.
Intermittent attempts have been made using modern mining techniques to identify and exploit further reserves including the Anglesey Copper Mines (1962), Canadian Industrial Gas and Oil Company (1966-70), Cominco (1973) and Angelsey Mining Company (1988-2018).
The result of all this activity is a severely damaged landscape that is brightly coloured and other worldly with many relics and structures from its use over the centuries. These include the site of the Great Opencast, Windmill, Pearl Shaft Engine House, Central Precipitation Pits, Dyffryn Adda reverberatory furnace and Mona smelting site. It is both a Site of Special Scientific Interest (SSSI) and a Scheduled Ancient Monument (SAM) which give it legal protections.
Further information and a surface trail leaflet: The Copper Kingdom. A visitor centre is located at the nearby harbour of Amlwch where the ore was loaded on to ships and transported.
Parys Underground Group explore and research the undergound workings and offer occasional visits. Their website contains a detailed resource on the history, geology and social aspects of the mine.
