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Countryside Council for Wales
Landscape & wildlife Please note - A new body, Natural Resources Wales has taken over all functions and services previously carried out by Countryside Council for Wales. While the Natural Resources Wales website continues to be developed, some online services will continue to be provided on this web site.


Elenydd SSSI is of national importance for features of Earth science and biological interest. A range of Earth science features is present. These include exposures of Silurian rocks, found north of Caban Coch Dam, which are crucial in helping to interpret the environments that existed in this part of Wales during late Ordovician and early Silurian times. Mineral-bearing spoil tips and rock exposures at Cwmystwyth Mine are important for the study of mineralisation in the Central Wales Orefield. The glacial landforms at Cwm Ddu and Cwm Tinwen provide important information about late Pleistocene events and processes in central Wales, although their mode of formation remains a subject of debate. Peat and lake clays that accumulated at Gors Lwyd over the last 14,000 years contain microscopic plant remains that provide a detailed record of environmental and vegetational changes in mid-Wales. The Afon Elan at Gors Lwyd displays a wide range of nationally important river landforms, including terraces, meanders and abandoned channels.

Elenydd SSSI is one of the most important areas of hill land in Mid Wales for nature conservation. It supports a range of breeding birds of upland and woodland and is one of the two most important areas in Wales for upland species. Much of the hill vegetation is also important and the moorland plateau is largely covered by blanket bog vegetation of European importance. Three particularly interesting localities within the site are the watershed mires at the headwaters of the Rivers Elan and Claerwen, the well developed pool and hummock mire at Cors Lwyd and the eroded, but still actively growing, mire complex at Cors Gôch. These areas support rare plant species. Crags, scree slopes and stream gorges provide contrasting habitat types that support species that would otherwise be suppressed by grazing. Mountain lakes within the site support a number of rare species, including the internationally rare Floating Water-plantain.

The area also includes a number of areas of considerable historic interest.

Elenydd SSSI aerial photo

©Infoterra Ltd 2010

Managing this site

The site includes Nant Irfon National Nature Reserve(NNR), owned and managed by the Countryside Council for Wales and Claerwen NNR managed by CCW in partnership with the owners Elan Valley Trust. The remainder of the site is owned by the Forestry Commission, Welsh Water, Brecknock Wildlife Trust, Crown Estates, the National Trust and a number of private owners. The special features of this SSSI and CCW’s views about site management have been summarised in a Site Management Statement, addressed to the owners and managers of the land. The statement can be found in the resource section below.

Access information

A large proportion of the site is designated CROW access land and is crossed by a number of public rights of way. Delails on access to Nant Irfon National Nature Reserve (NNR) and Claerwen NNR can be found in the links below. For detailed maps and information regarding access visit our access map via the resource section below.

Other information

The site includes or forms part of the Elenydd and Coetiroedd Cwm Elan/ Elan Valley Woodlands Special Areas of Conservation and the Elenydd-Mallaen Special Protection Area.

The mountainous area at the head of the Elan, Severn, Teifi, Wye and Tywi was called Elennydd, which means ‘area adjoining the river Elan’. River-names often reflect animal-names and Elennydd is probably from elain ‘hind, fawn’ followed by the territorial affix –ydd.




Access map

This is a link to Outdoor Wales on Line

Nant Irfon National Nature Reserve

This is a link to the Nant Irfon National Nature Reserve page

Claerwen National Nature Reserve

This is a link to the Claerwen National Nature Reserve page

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The landscapes team [SSSI]
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LL57 2DW
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0845 1306229
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