The site comprises the cliffs on the western side of Holy Island, which are formed from geologically complex and impressively folded strata rising to 120 m. There are also many small offshore stacks and islets. The IBA is important for seabirds and other cliff-breeders.
BirdLife International (2021) Important Bird Areas factsheet: Glannau Ynys Gybi/Holy Island Coast. Downloaded from
http://www.birdlife.org on 05/12/2021.