Northern Ireland, like the rest of the British Isles, is dotted with hillforts. The Atlas of Hillforts of Britain and Ireland lists thirty-two such forts. These are classically defined as small hilltop settlements fortified with earthworks, but many are not located on hills, and probably did not function as forts. Their function is unclear; although conventionally interpreted as defensive fortifications and centres of economic political power, there is little evidence that they were ever attacked, and more recent scholarship has suggested that they may be better interpreted as monuments.
County Antrim
Ballygill North (Rathlin Island) (), promontory fort
Carncoagh (), contour fort
Carnduff (), promontory fort
Carravindoon (Rathlin Island) (), promontory fort
Carrickagile (Rathlin Island) (), promontory fort
Derrynaseer (), contour fort
Dooninish (), promontory fort
Dunineny Castle (), promontory fort
Dunmull (), partial contour fort
Galboly Lower (), promontory fort
Knockdhu (), promontory fort
Larrybane (), promontory fort
Lurigethan (), promontory fort
Lyles Hill (), partial contour fort
McArt's Fort (), promontory fort
County Armagh
Forkill (), contour fort
Haughey's Fort (), multiple enclosure hillfort
Lisbanoe (), multiple enclosure hillfort
County Down
Coolnacran in Whyte's Estate, Loughbrickland. Downpatrick (), contour fort Dromorebrague (), contour fort Lisnagade (), earthen ringfort Magheraknock (), contour fort