View of the Great Opencast and associated spoil tips

What is ‘special’ about Mynydd Parys SSSI?

Mynydd Parys SSSI has two special features.

Mynydd Parys SSSI is of national importance for the wide-range of copper- and lead-bearing minerals that are found in spoil tips and rock exposures associated with numerous disused mines. The minerals are found in deposits that formed on an ancient sea floor, and this type of deposit (‘Kuroko’) is unique in Britain. Rare minerals found on this site include Pisanite, Antlerite, Basaluminite and Anglesite, for which Mynydd Parys is the type locality. The rich variety of minerals remaining both in the mine spoil and in the underground workings provide clues to the origin of these rocks and the conditions in which they formed.

Toxic metal tolerant lichens are only found on areas where the soil, rock or other surface on which they grow is rich in metals such as copper and zinc. 10 nationally scarce lichens have been recorded from this site, together with a nationally scarce liverwort. An assessment of lichens throughout the UK ranked this site second only to Coniston copper mines (which supported similar species but a greater variety).

As well as the features within the SSSI, listed above, Mynydd Parys has other features that contribute to the special interest. These include areas of heathland and wetland. This mixture of habitats is important for wildlife, including chough which nest on site. Mynydd Parys also supports stag’s horn clubmoss (Lycopodium clavatum) at its only known location on Anglesey. Unless specified below, management of this site should aim to look after these habitats and species as well as the listed features of interest.

What do we want Mynydd Parys SSSI to look like?

The mineralogical features should be visible and accessible to allow further study and research. This will be achieved by maintaining the current quantity of the mineral-bearing spoil, although it is accepted that some mineral specimens will be removed for the purposes of education and research. This will ensure that Mynydd Parys SSSI remains one of the best localities for the study of this type of copper mineralisation.

The areas notified for lichens should continue to support the rare species currently known from the site; these species should be in good health, producing healthy reproductive structures. The areas will be undisturbed by vehicles or pedestrians. The buildings will be sensitively maintained, to ensure that they continue to support lichens without suffering any loss of archaeological interest. Heathland will develop naturally on spoil heaps.

The spectacular mineralization found at Mynydd Parys can be studied in spoil tips as well as the mineral veins (left).

Folded rocks (left) and igneous rhyolite (right) help date the rocks and provide clues as to how the minerals formed.

What management is needed on Mynydd Parys SSSI and why?

Mynydd Parys is an excellent place for geology and wildlife. Sites such as this are vital for scientific study. However it will only remain so if the necessary management continues. CCW will work with you to ensure that this management is carried out.

What does this mean in practice?

There are a number of different factors that could damage the special features at Mynydd Parys if they are not properly managed. These are the ones we regard as most important:

Mining: There is valid planning permission for mining on the Mountain. Should the mine be reopened it is likely that parts of the SSSI would be altered, and close liaison with the mine operators will be needed to minimise impacts on the geological and botanical features.

Removal of spoil: Many of the rare lichens found on this site grow on the surface of spoil heaps, often on rocks that have lain unmoved for a century or more. If these stones are disturbed at all, such rarities may be damaged or destroyed. Removal of spoil could also be detrimental to the mineral interest and should be avoided other than small samples for educational/research purposes.

Land reclamation: Any remediation work (e.g. liming or top-soiling) which would lead to loss of rock exposure, removal of mine spoil or alteration of the chemical environment affecting the lichen interest, should be avoided.

Public access: The site is used for various activities including walking and by educational and research groups. This is not damaging but if people create new paths, lichens could be damaged.

Off-road vehicles: The use of vehicles, either for recreational purposes or associated with mining or other work on site, could cause major damage to lichens if they are driven away from the existing tracks. Trail biking, fly tipping and other unlawful uses could cause severe damage to lichen areas and should be discouraged by all available means.

Educational access: Educational groups studying the geology, archaeology and wildlife should remain on the paths most of time. Some of the minerals found here are a rare and finite resource and the lichens are particularly fragile, so the indiscriminate hammering of rocks is to be discouraged. As far as possible, educational groups studying geology should avoid areas notified for lichens, as trampling could damage lichens.

Archaeological restoration

Many of the buildings on site are scheduled ancient monuments; they are also in a poor state of repair and it is possible that work may be necessary to consolidate them. This could impact on lichens growing on or near them, nearby geological sites or on nesting chough. Good liaison will be needed between CCW, and any parties involved.

Tipped rubbish

Rubbish has been deposited on site, including vehicles and tyres in the Great Opencast, as revealed by recent drainage works. Whilst not damaging the scientific interest they are unsightly and may be removed from the site. Japanese knotweed, introduced with rubbish could spread and shade out lichens. It should not be allowed to spread from current locations (and might usefully be eradicated from these). Further tipping should be discouraged.


Our knowledge of wildlife is far from complete. It is possible that new features of value may appear and new management issues may arise in the future, whilst other issues may disappear. This statement is written with the best information we have now, but may have to change in the future as our understanding improves. Any information you can provide on the wildlife of your site, its management and its conservation would be much appreciated.

If you would like to discuss any aspect of your SSSI, or have any concerns about your SSSI, please contact your local CCW office.

Your local office is;

Cyngor Cefn Gwlad Cymru/Countryside Council for Wales

Llys y Bont,

Ffordd y Parc,

Parc Menai,


Gwynedd, LL57 4BN,

Telephone: 01248 672500

Fax: 01248 679259

Telephone 01248 672500

Fax: 01248 679259