Clogwyni Pen Llyn/ Seacliffs of Lleyn

Site details

UK map showing location of Clogwyni Pen Llyn/ Seacliffs of Lleyn Special Area of Conservation/Site of Community Importance.
Location of Clogwyni Pen Llyn/ Seacliffs of Lleyn SAC/SCI/cSAC


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

1230 Vegetated sea cliffs of the Atlantic and Baltic Coasts
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.