Sceilg Mhichíl is also one of Ireland’s most important sites for breeding seabirds, both for the diversity of the species and the size of the colonies it supports. Criterion (iii): Sceilg Mhichíl illustrates, as no other property can, the extremes of a Christian monasticism characterizing much of North Africa, the Near East and Europe. The Monastery and Hermitage on Sceilg Mhichíl represent a unique artistic achievement. Sceilg Mhichíl is approximately 21.9 ha in size. Sceilg Mhichíl, because of its isolation, has been protected from alterations and adaptations, other than those of the 19th century lighthouse builders.