The Ring of Gullion (Irish: Fáinne Cnoc Shliabh gCuillinn, meaning "hill ring of Slieve Gullion") is a geological formation and area, officially designated as an Area of Outstanding Natural Beauty, (AONB) located in County Armagh, Northern Ireland. The area centres on Slieve Gullion, the highest peak in County Armagh, measures roughly 42 by 18 kilometres (26 by 11 mi) and comprises some 150 km² defined topographically by the hills of an ancient ring dyke. Parts of the area have also been officially listed as Areas of Special Scientific Interest.