Erris Head has been designated a Special Area of Conservation (SAC) under the European Union's Habitats Directive. Erris Head SAC comprises approximately of cliff plus adjoining habitats. The geology of the region consists of acid rocks, such as quartzite, gneiss and Silurian schists and slates. The sea cliffs are very exposed and subject to very high rainfall. They are of moderate height, reaching a maximum of about in the north-east and are predominantly north-facing. Vegetation here includes such species as roseroot and rock sea-spurrey.