“ …..an Earagal árd , ina stua os cionn caor 's call”
Photograph by Gareth Wray PhotographyAn Earagail/Errigal
At 751 metres above sea level, the quartzite peak of Errigal – an Earagail - dominates the landscape of the north-west of county Donegal.
Located within a Special Area of Conservation (SAC), it comprises a complex geology of schist, quartzite and limestone while its surrounding area supports a range of habitats including blanket bog, wet and dry heaths and exposed rock and scree. It is a place of exceptional geological, botanical and zoological value with a wide range of plant and animal species including many which are rare or under threat.
What is particularly significant about the area is the sheer extent of its relatively unmodified habitat, including within the SAC, the largest area of intact blanket bog in the northwest of Ireland. Its significant natural heritage is complemented by a wealth of cultural assets and attributes which trace the story of settlement from earliest times to the present day. Located within the Donegal Gaeltacht, its place names, folklore, oral traditions, and vital communities add immeasurably to the distinctiveness of this area and its unique sense of place.
Google Earth Tour of Errigal
Take a tour of Errigal and learn how the mountain was formed
The Geology
Photograph by Gareth Wray PhotographyErrigal (An Earagail) is a 751-metre (2,464 ft) mountain near Glenveagh National Park in County Donegal, Ireland. It is the tallest peak of the Derryveagh Mountains and the tallest peak in County Donegal. Errigal is also the most southern and the highest of the mountain chain called the "Seven Sisters" by locals.
This mountain chain contains some of the oldest rocks in Ireland. They are metasedimentary rocks of the Lower Dalradian age (700-600 million years ago). Around 470-450 million years ago, tectonic plate collisions produced high temperatures and high pressures and converted mudstone to schists, and sandstone to quartzites.
There are also classical features associated with former glaciation – the deep valley containing Altan Lough, and the numerous erratic boulders of granite that were carried here by the ice from the ridge of nearby Dooish . At the bottom of the northeast face of Errigal the mounds and ridges of quartzite boulders are the consequence of a huge landslide that occurred about 17,000 years ago as the last glaciers were melting. Similar features, but with a more extensive cover of vegetation, can be seen from the summit ridge at the foot of the southwest and west-facing slopes. Errigal was previously a much bulkier mountain than it is today and underwent dramatic reshaping because of these landslides. Since then, repeated episodes of rockfall associated with freezing and thawing have created the spectacular screes that surround the mountain.
Errigal Mountain is contained within the designated Natura 2000 sites of Clogherhagore Bog and Glenveagh National Park Special Area of Conservation and Derryveagh and Glendowan Mountains Special Protected Area.
Take a tour of Errigal on Google Earth
The Habitat
Errigal mountain is primarily an upland area. Its national importance in terms of biodiversity conservation is unquestionable since it contains numerous upland habitat types listed under Annex I of the EU Habitats Directive, as well as many rare and threatened birds associated with these habitats.
A habitat map based on the Level 2 of the Fossitt 2000 habitat classification system shows that the greatest area of the footprint is occupied by blanket bogs (both lowland and upland) and in mosaic with dry siliceous heath. A large area of wet heath has been identified at the foot of the south-eastern slope of Errigal. Above c.400m, the main habitat consists of ‘siliceous scree and loose rock’ while, at the ridge, some dry heath and alpine heath is also present. Some glacial till and bedrock are exposed near the stream and up to the coll