The Antrim Hills site comprises two land units: the northern, larger section extends between Carnanmore and Soarne’s Hill, including Ballypatrick Forest, Slieveanorra Forest, Breen Wood and Glenariff/Cleggan Forest, mainly including land above the 220m contour the southern section comprises the area bounded by Capanagh, Ballyboley and Douglas Top
Both sections are delimited principally by physical boundaries closest to merged radii extending 2.5km from nest sites used by hen harriers between 1997 and 2004.
Antrim Hills qualifies under Article 4.1 of the Directive (79/409/EEC) by supporting nationally important populations of hen harrier and merlin. The site encompasses all lands within these boundaries, excluding wholly-improved pasture, arable land, buildings and associated lands. It includes coniferous plantations, blanket bog, wet and dry heath, grass moor, scrub, inland cliff and limited semi-improved agricultural grassland. The principal interests are the breeding populations of hen harrier and merlin.