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Special Areas of Conservation

Clogwyni Pen Llŷn/ Seacliffs of Lleyn

Designated Special Area of Conservation (SAC)
Country Wales
Unitary Authority West Wales and The Valleys
Centroid* SH216257
Latitude 52.8
Longitude -4.646388889
SAC EU Code UK0030271
Status Designated Special Area of Conservation (SAC)
Area (ha) 1045.02
* This is the approximate central point of the SAC. In the case of large, linear or composite sites, this may not represent the location where a feature occurs within the SAC.
Location of Clogwyni Pen Llŷn/ Seacliffs of Lleyn SAC

General site character

  • Marine areas, Sea inlets (5%)
  • Coastal sand dunes, Sand beaches, Machair (13%)
  • Shingle, Sea cliffs, Islets (70%)
  • Heath, Scrub, Maquis and Garrigue, Phygrana (10%)
  • Broad-leaved deciduous woodland (2%)

Download the Standard Data Form for this site as submitted to Europe (PDF <100kb)

Note When undertaking an appropriate assessment of impacts at a site, all features of European importance (both primary and non-primary) need to be considered.

Annex I habitats that are a primary reason for selection of this site

  • The SAC includes two, mainly soft cliff, sites on the Lleyn Peninsula – one on the south coast which stretches between Porth Neigwl and Porth Ceiriad, and one on the north coast which includes the cliffs between Porth Dinllaen and Porth Pistyll. The Porth Neigwl site includes an uninterrupted stretch of soft cliffs mainly composed of eroding glacial till, but about 1.5 km at the eastern end is overlain by sand dunes. An important feature of the site is that the cliffs are south-facing and the additional solar gain makes them very good for invertebrates, including some threatened and scarce species. Because the cliffs are very dynamic, most of the cliff face is devoid of vegetation, but where flushes occur creeping-bent Agrostis stolonifera and sea mayweed Tripleurospermum maritimum have become established, and there is a patch of great horsetail Equisetum telmateia at the western end. The cliff-top vegetation is very varied and ranges from mobile dune vegetation with marram Ammophila arenaria on the perched dunes at the eastern end to maritime grasslands with red fescue Festuca rubra, thrift Armeria maritima, and buck’s-horn plantain Plantago coronopus on the boulder clay, but in other areas agricultural land extends to the cliff edge. The cliffs at the Porth Dinllaen site are north-facing and therefore of only moderate interest for invertebrates, but still support several notable species. However, the vegetation is very diverse and on the slopes ranges from ruderal communities with colt’s-foot Tussilago farfara to grasslands and scrub with blackthorn Prunus spinosa and gorse Ulex europaeus. There are also some base-rich flushes. In the more stable areas these include a type of calcicolous mire with black bog-rush Schoenus nigricans, great horsetail Equisetum telmateia and common reed Phragmites australis, whereas in the more eroded areas, especially where slumping is taking place exposing base-rich soils, pioneer bryophyte and lichen assemblages occur. The cliff-top vegetation includes various grassland and scrub communities, but as a result of agricultural development it has been reduced to a fairly narrow zone in some places.

Annex I habitats present as a qualifying feature, but not a primary reason for selection of this site

  • Not Applicable

Annex II species that are a primary reason for selection of this site

  • Not Applicable

Annex II species present as a qualifying feature, but not a primary reason for site selection

  • Not Applicable

Many designated sites are on private land: the listing of a site in these pages does not imply any right of public access.