| Site Number | Site Name | County | Description | |
| ASSI304 | Aghabrack | Co. Tyrone | | Details... |
| ASSI228 | Aghanloo Wood | Co. Londonderry | Aghanloo is important because it is one ... | Details... |
| ASSI085 | Aghnadarragh | Co. Antrim | Aghnadarragh is an artificial outcrop in... | Details... |
| ASSI171 | Altikeeragh | Co. Londonderry | An area of intact blanket bog within a l... | Details... |
| ASSI059 | Altmover Glen | Co. Londonderry | The Altmover Glen was formed by the Wood... | Details... |
| ASSI121 | Annachullion Lough | Co. Fermanagh | Physiographical interest of this largely... | Details... |
| ASSI038 | Annacramph Meadows | Co. Armagh | Annacramph Meadows ASSI, a 2.5 hectare ... | Details... |
| ASSI308 | Annaghagh Bog | Co. Tyrone | | Details... |
| ASSI149 | Aughnadarragh Lough | Co. Down | The area is particularly notable as one ... | Details... |
| ASSI150 | Ballybannan | Co. Down | The site forms part of shallow basin in ... | Details... |
| ASSI151 | Ballycam | Co. Down | Shallow inter-drumlin hollow. Varied co... | Details... |
| ASSI045 | Ballycarry | Co. Antrim | The area is of special scientific intere... | Details... |
| ASSI147 | Ballycastle Coalfield | Co. Antrim | Ballycastle Coalfield is the best exposu... | Details... |
| ASSI043 | Ballygill North | Co. Antrim | The area is of special scientific intere... | Details... |
| ASSI153 | Ballykilbeg | Co. Down | Ballykilbeg is a large wetland site with... | Details... |
| ASSI194 | Ballyknock | Co. Londonderry | Ballyknock represents a series of field ... | Details... |
| ASSI260 | Ballymacaldrack | Co. Antrim | | Details... |
| ASSI257 | Ballymacallion | Co. Londonderry | | Details... |
| ASSI072 | Ballymacombs More | Co. Londonderry | Ballymacombs More ASSI is important beca... | Details... |
| ASSI003 | Ballymacormick Point | Co. Down | Ballymacormick Point is a rocky headland... | Details... |
| ASSI152 | Ballynagross Lower | Co. Down | A shallow sided valley in undulating enc... | Details... |
| ASSI010 | Ballynahone Bog | Co. Londonderry | The area is of special scientific intere... | Details... |
| ASSI217 | Ballynanaghten | Co. Antrim | The two fields at Ballynanaghten are typ... | Details... |
| ASSI243 | Ballypalady | Co. Antrim | Ballypaladay Plant Bed ASSI is one of th... | Details... |
| ASSI087 | Ballyquintin Point | Co. Down | Ballyquintin Point exhibits an exception... | Details... |
| ASSI266 | Ballyrisk More | Co. Londonderry | | Details... |
| ASSI133 | Ballysudden | Co. Tyrone | Ballysudden contains some of the finest... | Details... |
| ASSI252 | Banagher | Co. Fermanagh | Banagher ASSI is a complex mosaic of wet... | Details... |
| ASSI064 | Banagher Glen | Co. Londonderry | Banagher Glen is the largest intact bloc... | Details... |
| ASSI208 | Bann Estuary | Co. Londonderry | Bann Estuary incorporates a series of sa... | Details... |
| ASSI098 | Bardahessiagh | Co. Tyrone | A highly fossiliferous sequence of Ordov... | Details... |
| ASSI016 | Beagh Big | Co. Fermanagh | This area is special scientific interest... | Details... |
| ASSI120 | Bellanaleck | Co. Fermanagh | One of the most important geological loc... | Details... |
| ASSI100 | Benburb | Co. Tyrone | The only interglacial peat deposit known... | Details... |
| ASSI212 | Binevenagh | Co. Londonderry | The area is of special scientific intere... | Details... |
| ASSI007 | Black Bog | Co. Tyrone | This site is now thought to be the large... | Details... |
| ASSI143 | Black Burn | Co. Antrim | Black Burn Cave is the only known extens... | Details... |
| ASSI154 | Black Lough | Co. Down | Black Lough is a large, complex site. We... | Details... |
| ASSI239 | Black Lough | Co. Tyrone | Black Lough is a small lake near Aughnac... | Details... |
| ASSI298 | Blackslee | Co. Fermanagh | | Details... |
| ASSI144 | Boho | Co. Fermanagh | Boho is the only example of a joint cont... | Details... |
| ASSI227 | Bonds Glen | Co. Londonderry | Bond’s Glen is special because of its ra... | Details... |
| ASSI092 | Bovevagh | Co. Londonderry | Bovevagh is an early Midlandian prograde... | Details... |
| ASSI108 | Braade | Co. Fermanagh | Braade is a scarp cliff in the middle of... | Details... |
| ASSI339 | Brackagh Bog | Co. Armagh | | Details... |
| ASSI161 | Breen Wood | Co. Antrim | Breen Wood is a semi-natural, acid woodl... | Details... |
| ASSI334 | Brookend | Co. Tyrone | | Details... |
| ASSI081 | Burdautien Lough | Co. Fermanagh | Physiographic interest is of the presenc... | Details... |
| ASSI123 | Caldanagh Bog | Co. Antrim | A compact lowland raised bog within the ... | Details... |
| ASSI342 | Caledon and Tynan | Co. Armagh | | Details... |
| ASSI342 | Caledon and Tynan | Co. Tyrone | | Details... |
| ASSI231 | Cam Lough | Co. Armagh | Cam Lough is a mid-altitude lake that li... | Details... |
| ASSI289 | Camlough Quarry | Co. Armagh | | Details... |
| ASSI302 | Carey Valley | Co. Antrim | | Details... |
| ASSI103 | Carlingford Lough | Co. Armagh | The limestones of Carlingford Lough were... | Details... |
| ASSI103 | Carlingford Lough | Co. Down | The limestones of Carlingford Lough were... | Details... |
| ASSI167 | Carn/Glenshane Pass | Co. Londonderry | Carn/Glenshane Pass represents a very la... | Details... |
| ASSI116 | Carrickarade | Co. Antrim | The island of Carrickarade and the adjoi... | Details... |
| ASSI215 | Carrickastickan | Co. Armagh | The two fields at Carrickastickan are ty... | Details... |
| ASSI001 | Carrickbrawn | Co Cavan | The area is of special scientific intere... | Details... |
| ASSI156 | Carrowcarlin | Co. Down | Carrowcarlin is a basin wetland supporti... | Details... |
| ASSI189 | Cashel Loughs | Co. Armagh | Cashel Loughs is an extensive area of se... | Details... |
| ASSI313 | Cashel Rock | Co. Tyrone | | Details... |
| ASSI157 | Castle Enigan | Co. Down | Castle Enigan is an extensive inter-drum... | Details... |
| ASSI286 | Castle Point | Co. Antrim | | Details... |
| ASSI259 | Castle River Valley | Co. Londonderry | | Details... |
| ASSI193 | Castletown | Co. Antrim | Castletown is a series of four fields co... | Details... |
| ASSI230 | Castlewellan Lake | Co. Down | The site, Castlewellan Lake, is a mid-al... | Details... |
| ASSI327 | Church Bay | Co. Antrim | | Details... |
| ASSI200 | Cladagh (Swanlinbar) River | Co. Fermanagh | The Cladagh (Swanlinbar) River rises hig... | Details... |
| ASSI026 | Cleggan Valley | Co. Antrim | The site runs along the lower, southern ... | Details... |
| ASSI301 | Cloghfin Port | Co. Antrim | | Details... |
| ASSI293 | Cloghinny | Co. Armagh | | Details... |
| ASSI242 | Conagher | Co. Fermanagh | Conagher ASSI is of particular importanc... | Details... |
| ASSI315 | Coolcran | Co. Fermanagh | | Details... |
| ASSI267 | Coolnasillagh | Co. Londonderry | | Details... |
| ASSI232 | Copeland Islands | Co. Down | Copeland Islands ASSI is located off the... | Details... |
| ASSI155 | Corbally | Co. Down | Corbally is an inter-drumlin wetland. Th... | Details... |
| ASSI197 | Corbylin Wood | Co. Tyrone | Corbylin Wood has several distinctive pl... | Details... |
| ASSI048 | Corraslough Point | Co. Fermanagh | This site comprises of a number of low-l... | Details... |
| ASSI115 | Craigahulliar | Co. Antrim | The features of geological interest in C... | Details... |
| ASSI164 | Craigantlet Woods | Co. Down | Craigantlet Woods ASSI is composed of th... | Details... |
| ASSI124 | Cranny Bogs | Co. Tyrone | Cranny Bogs represent a series of three ... | Details... |
| ASSI055 | Crockaghole Wood | Co. Londonderry | This site is of special scientific inter... | Details... |
| ASSI183 | Crossbane Lough | Co. Armagh | Crossbane Lough is a large, diverse site... | Details... |
| ASSI263 | Cruninish Island | Co. Fermanagh | | Details... |
| ASSI069 | Cuilcagh Mountain | Co. Fermanagh | Cuilcagh mountain is of Special Scientif... | Details... |
| ASSI223 | Cullentra Lough | Co. Tyrone | Situated in an inter-drumlin wetland thi... | Details... |
| ASSI053 | Culnafay | Co. Antrim | Unique diatomite and associated material... | Details... |
| ASSI074 | Curran Bog | Co. Londonderry | Curran Bog occurs in the flood-plain of ... | Details... |
| ASSI125 | Dead Island Bog | Co. Londonderry | A large, relatively intact lowland raise... | Details... |
| ASSI041 | Dernish Island | Co. Fermanagh | Island with area of swamp, fen and grass... | Details... |
| ASSI035 | Deroran Bog | Co. Tyrone | Deroran Bog is typical of the western bo... | Details... |
| ASSI237 | Derrycloony Lough | Co. Tyrone | Derrycloony Lough is a small lake east o... | Details... |
| ASSI079 | Derryleckagh | Co. Down | Derryleckagh Wood is notable for its int... | Details... |
| ASSI221 | Derryvore | Co. Armagh | Isolated remnant of the once extensive w... | Details... |
| ASSI269 | Devenish Island | Co. Fermanagh | | Details... |
| ASSI279 | Dromore | Co. Tyrone | | Details... |
| ASSI122 | Drumacrittin Lough | Co. Fermanagh | Physiographical interest of this largely... | Details... |
| ASSI322 | Drumbegger | Co. Fermanagh | | Details... |
| ASSI182 | Drumcarn | Co. Armagh | Drumcarn is a large site with a wide ran... | Details... |
| ASSI240 | Drumcrow | Co. Tyrone | Drumcrow is an important site because of... | Details... |
| ASSI281 | Drumharvey | Co. Tyrone | | Details... |
| ASSI056 | Drumlea and Mullan Woods | Co. Tyrone | Drumlea & Mullan Woods is the 3rd larges... | Details... |
| ASSI020 | Drumlisaleen | Co. Fermanagh | This site consists of seven small hay me... | Details... |
| ASSI205 | Drumlougher Lough | Co. Armagh | Drumlougher Lough is a large, diverse si... | Details... |
| ASSI009 | Dunloy Bog | Co. Antrim | Dunloy Bog contains one of the largest r... | Details... |
| ASSI274 | Dunnaree Hill | Co. Tyrone | | Details... |
| ASSI095 | Eastern Mournes | Co. Down | The area is of special scientific intere... | Details... |
| ASSI234 | Edenaclogh Wood | Co. Fermanagh | Edenaclough Wood is a special place beca... | Details... |
| ASSI256 | Errigal Glen | Co. Londonderry | | Details... |
| ASSI061 | Ervey Wood | Co. Londonderry | Ervey Wood ASSI covers an area of 25.2ha... | Details... |
| ASSI134 | Essan Burn and Mullyfamore | Co. Tyrone | A large area of blanket bog in the Essan... | Details... |
| ASSI008 | Fairy Water Bogs | Co. Tyrone | The area is of special scientific intere... | Details... |
| ASSI141 | Fardross Stream | Co. Tyrone | Fardross Stream cuts through rocks that ... | Details... |
| ASSI138 | Fardrum & Roosky Turloughs | Co. Fermanagh | Fardrum and Roosky are the only positive... | Details... |
| ASSI238 | Fathom Upper | Co. Armagh | Fathum Upper ASSI is a species rich Gras... | Details... |
| ASSI251 | Feystown | Co. Antrim | Feystown ASSI is a small area of semi-na... | Details... |
| ASSI110 | Finn Floods | Co. Fermanagh | This site consist of the unmodified matu... | Details... |
| ASSI126 | Frosses Bog | Co. Antrim | A compact, relatively undisturbed lowlan... | Details... |
| ASSI224 | Fymore Lough | Co. Tyrone | Situated in an inter-drumlin wetland thi... | Details... |
| ASSI067 | Garron Plateau | Co. Antrim | The Garron Plateau is the largest area o... | Details... |
| ASSI004 | Garry Bog | Co. Antrim | This site is important as it contains on... | Details... |
| ASSI127 | Garry Bog Part II | Co. Antrim | This site liesadjacent to Garry Bog ASSI... | Details... |
| ASSI017 | Garvros | Co. Fermanagh | This site is of interest because of the ... | Details... |
| ASSI202 | Giant's Causeway and Dunseverick | Co. Antrim | The Giant’s Causeway is the most renowne... | Details... |
| ASSI287 | Glarryford | Co. Antrim | | Details... |
| ASSI024 | Glen Burn | Co. Antrim | The site consists of a small narrow vall... | Details... |
| ASSI331 | Glen East | Co. Fermanagh | | Details... |
| ASSI025 | Glenariff | Co. Antrim | Largest area of undisturbed semi-natural... | Details... |
| ASSI023 | Glenarm Woods | Co. Antrim | The site is fragmented and consists of f... | Details... |
| ASSI254 | Glenballyemon River | Co. Antrim | | Details... |
| ASSI292 | Glendesha | Co. Armagh | | Details... |
| ASSI057 | Glenmore Wood | Co. Tyrone | The area is of special scientific intere... | Details... |
| ASSI168 | Glennasheevar | Co. Fermanagh | Large area of intact oceanic blanket bog... | Details... |
| ASSI002 | Gortnagory | Co. Antrim | Colony of nationally-rare orchid Spirant... | Details... |
| ASSI196 | Grange Wood | Co. Tyrone | Grange Wood has a wide range of woodland... | Details... |
| ASSI319 | Gravel Ridge Island | Co. Fermanagh | | Details... |
| ASSI160 | Greenan | Co. Down | Greenan is a basin fen. Although small, ... | Details... |
| ASSI158 | Greenan Lough | Co. Down | Greenan Lough includes open water, reedb... | Details... |
| ASSI139 | Ground Bridge | Co. Fermanagh | A short, active river cave, where the Ro... | Details... |
| ASSI264 | Hare Island | Co. Fermanagh | | Details... |
| ASSI132 | Heron and Carrigullian Loughs | Co. Down | Heron & Carrigullian Loughs, together wi... | Details... |
| ASSI211 | Hollymount | Co. Down | Hollymount represents an area of well-de... | Details... |
| ASSI040 | Horse Island | Co. Fermanagh | Horse Island is a lightly grazed drumlin... | Details... |
| ASSI054 | Inishroosk | Co. Fermanagh | This is an area of special scientific in... | Details... |
| ASSI029 | Inner Belfast Lough | Co. Antrim | This area encompasses the southern part ... | Details... |
| ASSI029 | Inner Belfast Lough | Co. Down | This area encompasses the southern part ... | Details... |
| ASSI324 | Keadew | Co. Fermanagh | | Details... |
| ASSI086 | Killard | Co. Down | Killard Point is of special scientific i... | Details... |
| ASSI225 | Killough Bay and Strand Lough | Co. Down | Killough Bay and Strand Lough ASSI is co... | Details... |
| ASSI076 | Killymackan Lough | Co. Fermanagh | Killymackin Lough, a satellite lake of l... | Details... |
| ASSI207 | Kilnameel | Co. Fermanagh | Kilnameel is a series of fields containi... | Details... |
| ASSI078 | Kilroosky Lough | Co. Fermanagh | The chemical composition of water in thi... | Details... |
| ASSI031 | Kiltubbrid Loughs | Co. Armagh | This site comprises a large basin contai... | Details... |
| ASSI044 | Kinramer South | Co. Antrim | This area of rathlin Island was declare... | Details... |
| ASSI275 | Kirlish | Co. Tyrone | | Details... |
| ASSI014 | Knockballymore Lough | Co. Fermanagh | Physiographic interest is of the presen... | Details... |
| ASSI307 | Knocknacloy | Co. Tyrone | | Details... |
| ASSI297 | Knocknashangan | Co. Fermanagh | | Details... |
| ASSI166 | Knockninny Hill | Co. Fermanagh | Knockninny Hill is a residual block of h... | Details... |
| ASSI037 | Lackan Bog | Co. Down | This site is the largest single block of... | Details... |
| ASSI111 | Largalinny | Co. Fermanagh | Mature semi-natural woodland , typically... | Details... |
| ASSI314 | Largy Quarry | Co. Fermanagh | | Details... |
| ASSI106 | Larne Lough | Co. Antrim | Larne Lough is a sea lough approximately... | Details... |
| ASSI169 | Leathemstown | Co. Antrim | Leathemstown is an area of marginal agri... | Details... |
| ASSI250 | Lemnalary | Co. Antrim | Lemnalary ASSI is a small area of agricu... | Details... |
| ASSI236 | Lenaghan Wood | Co. Fermanagh | Lenaghan Wood is a special place because... | Details... |
| ASSI019 | Lergan | Co. Fermanagh | Lergan slopes north to south with the so... | Details... |
| ASSI214 | Levallymore | Co. Armagh | Levallymore is a series of fields with s... | Details... |
| ASSI096 | Limehill Farm | Co. Tyrone | The type locality for the zonal graptoli... | Details... |
| ASSI341 | Linford | Co. Antrim | | Details... |
| ASSI278 | Lisdoo | Co. Tyrone | | Details... |
| ASSI290 | Lislea | Co. Armagh | | Details... |
| ASSI288 | Lisnaragh | Co. Tyrone | | Details... |
| ASSI323 | Little Deer Park | Co. Antrim | | Details... |
| ASSI097 | Little River | Co. Tyrone | An important historical palaeontological... | Details... |
| ASSI248 | Lough Aleater | Co. Fermanagh | Lough Aleater is a mid-altitude lake gen... | Details... |
| ASSI027 | Lough Beg | Co. Antrim | Lough Beg and its associated aquatic veg... | Details... |
| ASSI027 | Lough Beg | Co. Londonderry | Lough Beg and its associated aquatic veg... | Details... |
| ASSI294 | Lough Corr | Co. Tyrone | | Details... |
| ASSI249 | Lough Corry | Co. Fermanagh | Lough Corry is a mid-altitude lake gener... | Details... |
| ASSI226 | Lough Doo | Co. Tyrone | The Lough Doo area is of importance in u... | Details... |
| ASSI051 | Lough Foyle | Co. Londonderry | Lough Foyle is of particular interest be... | Details... |
| ASSI295 | Lough Gullion | Co. Armagh | | Details... |
| ASSI261 | Lough McCall | Co. Tyrone | | Details... |
| ASSI140 | Lough Melvin | Co. Fermanagh | Lough Melvin is a large mesotrophic loug... | Details... |
| ASSI262 | Lough na blaney bane | Co. Tyrone | | Details... |
| ASSI030 | Lough Neagh | Co. Antrim | Lough Neagh, the largest freshwater lake... | Details... |
| ASSI030 | Lough Neagh | Co. Armagh | Lough Neagh, the largest freshwater lake... | Details... |
| ASSI030 | Lough Neagh | Co. Down | Lough Neagh, the largest freshwater lake... | Details... |
| ASSI030 | Lough Neagh | Co. Londonderry | Lough Neagh, the largest freshwater lake... | Details... |
| ASSI030 | Lough Neagh | Co. Tyrone | Lough Neagh, the largest freshwater lake... | Details... |
| ASSI247 | Lough Scolban | Co. Fermanagh | Lough Scolban is a mid-altitude lake tha... | Details... |
| ASSI206 | Loughaveely | Co. Armagh | Loughaveely is a small site in an extend... | Details... |
| ASSI039 | Loughkeelan | Co. Down | A small eutrophic lough with high calciu... | Details... |
| ASSI159 | Loughmoney | Co. Down | A small site occupying a depression at t... | Details... |
| ASSI306 | Lower Creevagh | Co. Londonderry | | Details... |
| ASSI204 | Lurgan Lough | Co. Armagh | The wetlands associated with Lurgan Loug... | Details... |
| ASSI235 | Lurgan River Wood | Co. Fermanagh | Lurgan River Wood is a special place bec... | Details... |
| ASSI280 | Lurgylea | Co. Tyrone | | Details... |
| ASSI119 | Magheramenagh | Co. Fermanagh | It is one of only two Waulsortian mound ... | Details... |
| ASSI068 | Magilligan | Co. Londonderry | Magilligan is one of the best examples o... | Details... |
| ASSI317 | Makenny | Co. Tyrone | | Details... |
| ASSI128 | McKean's Moss | Co. Tyrone | The most extreme north - western example... | Details... |
| ASSI165 | McKean's Moss Part II | Co. Tyrone | McKean’s Moss Part II consists of a smal... | Details... |
| ASSI075 | Mill Lough | Co. Fermanagh | Mill Lough is an inter-drumlin lake (a s... | Details... |
| ASSI013 | Monawilkin | Co. Fermanagh | Monawilkin is of Special Scientific Inte... | Details... |
| ASSI018 | Moneendogue | Co. Fermanagh | This site is off special scientific inte... | Details... |
| ASSI005 | Moneygal Bog | Co. Tyrone | The area is of special scientific intere... | Details... |
| ASSI209 | Moneygal Bog Part II | Co. Tyrone | Moneygal Bog Part II represents an area ... | Details... |
| ASSI305 | Moneystaghan Bog | Co. Londonderry | | Details... |
| ASSI015 | Moninea Bog | Co. Fermanagh | Moninea Bog is one of the best remaining... | Details... |
| ASSI109 | Montiaghs Moss | Co. Antrim | Largely cutover lowland raised bog withi... | Details... |
| ASSI311 | Mountfield Quarry | Co. Tyrone | | Details... |
| ASSI180 | Moyrourkan Lough | Co. Armagh | Moyrourkan Lough is a large wetland with... | Details... |
| ASSI291 | Mullaghbane | Co. Armagh | | Details... |
| ASSI309 | Mullaghcarn | Co. Tyrone | | Details... |
| ASSI244 | Mullynaskeagh | Co. Fermanagh | Mulynaskeagh Clay Pit ASSI lies within a... | Details... |
| ASSI089 | Murlough | Co. Down | Physiographical: Coastal complex exhibit... | Details... |
| ASSI203 | Murrins | Co. Tyrone | The Murrins complex is a largely pristin... | Details... |
| ASSI060 | Ness Wood | Co. Londonderry | The majority of the woodland on this sit... | Details... |
| ASSI241 | Newlands | Co. Antrim | This site is composed of six fields and ... | Details... |
| ASSI022 | North Woodburn Glen | Co. Antrim | The site consist of North Woodburn Glen ... | Details... |
| ASSI105 | Outer Ards | Co. Down | Internationally important rock series su... | Details... |
| ASSI104 | Outer Belfast Lough | Co. Antrim | The site is important for the Ordovicia... | Details... |
| ASSI104 | Outer Belfast Lough | Co. Down | The site is important for the Ordovicia... | Details... |
| ASSI062 | Owenkillew and Glenelly Woods | Co. Tyrone | This site is the second largest semi-nat... | Details... |
| ASSI213 | Owenkillew River | Co. Tyrone | The Owenkillew River rises in Davagh For... | Details... |
| ASSI282 | Paris Island Big | Co. Fermanagh | | Details... |
| ASSI210 | Peatlands Park | Co. Armagh | Peatlands Park is of special scientific ... | Details... |
| ASSI065 | Pettigoe Plateau | Co. Fermanagh | Pettigoe plateau is the largest one of t... | Details... |
| ASSI101 | Portballintrae | Co. Antrim | Cliff exposure of glaciomarine, nearshor... | Details... |
| ASSI066 | Portmore Lough | Co. Antrim | Portmore Lough is of special scientific ... | Details... |
| ASSI177 | Portmuck | Co. Antrim | Portmuck contains the best exposure of t... | Details... |
| ASSI176 | Portrush West Strand | Co. Antrim | Portrush West Strand is of Special Scien... | Details... |
| ASSI170 | Quoile | Co. Down | Quoile is centred around the former tida... | Details... |
| ASSI113 | Ramore Head and The Skerries | Co. Antrim | An intrusion of Tertiary dolerite has pu... | Details... |
| ASSI033 | Rathlin Island - Coast | Co. Antrim | The coastal ASSI is of particular intere... | Details... |
| ASSI265 | Rathsherry | Co. Antrim | | Details... |
| ASSI255 | Rehaghy Wood | Co. Tyrone | Rehaghy Wood covers part of the lower so... | Details... |
| ASSI296 | River Faughan and Tributaries | Co. Londonderry | | Details... |
| ASSI296 | River Faughan and Tributaries | Co. Tyrone | | Details... |
| ASSI229 | River Foyle and Tributaries | Co. Tyrone | The ASSI includes the River Foyle and it... | Details... |
| ASSI246 | River Roe and Tributaries | Co. Londonderry | | Details... |
| ASSI299 | Ross | Co. Fermanagh | | Details... |
| ASSI178 | Rostrevor Wood | Co. Down | Rostrevor Wood is a mature Oak Woodland ... | Details... |
| ASSI268 | Round Lough & Lough Fadda | Co. Tyrone | | Details... |
| ASSI175 | Runkerry | Co. Antrim | A beach system of international importan... | Details... |
| ASSI285 | Sandy Braes | Co. Antrim | | Details... |
| ASSI083 | Scawt Hill | Co. Antrim | International type locality for a series... | Details... |
| ASSI091 | Scrabo | Co. Down | Exposure of the Triassic Sherwood Sandst... | Details... |
| ASSI300 | Scraghy | Co. Tyrone | | Details... |
| ASSI222 | Selshion | Co. Armagh | Isolated remnant of the once extensive w... | Details... |
| ASSI050 | Sheep Island | Co. Antrim | The area is of special scientific intere... | Details... |
| ASSI273 | Sheepland Coast | Co. Down | | Details... |
| ASSI245 | Shimna River | Co. Down | | Details... |
| ASSI195 | Silverbrook Wood | Co. Tyrone | Silverbrook Wood lies on a steep north-f... | Details... |
| ASSI077 | Slieve Beagh | Co. Fermanagh | Slieve Beagh is the third largest area o... | Details... |
| ASSI077 | Slieve Beagh | Co. Tyrone | Slieve Beagh is the third largest area o... | Details... |
| ASSI198 | Slieve Gullion | Co. Armagh | Slieve Gullion is one of the largest hea... | Details... |
| ASSI303 | Slieveanorra and Croaghan | Co. Antrim | | Details... |
| ASSI063 | Slievenacloy | Co. Antrim | Slievenacloy is an area of marginal agri... | Details... |
| ASSI276 | Sloughan and Willmount Glens | Co. Tyrone | | Details... |
| ASSI258 | Smulgedon | Co. Londonderry | | Details... |
| ASSI312 | Sruhanleanantawey Burn | Co. Londonderry | | Details... |
| ASSI058 | Strabane Glen | Co. Tyrone | Strabane Glen is a narrow valley support... | Details... |
| ASSI117 | Straduff | Co. Tyrone | The Upper Carboniferous rocks of the Dru... | Details... |
| ASSI179 | Straghans Lough | Co. Armagh | Straghans Lough is a large, diverse site... | Details... |
| ASSI162 | Straidkilly Wood | Co. Antrim | Straidkilly is one of the largest and le... | Details... |
| ASSI006 | Strangford Lough (Part 1) | Co. Down | Strangford Lough is one of the largest s... | Details... |
| ASSI032 | Strangford Lough (Part 2) | Co. Down | This coastal site comprises intertidal f... | Details... |
| ASSI034 | Strangford Lough (Part 3) | Co. Down | The Part 3 area is an integral part of t... | Details... |
| ASSI080 | Summerhill Lough | Co. Fermanagh | Physiographic interest is of the presen... | Details... |
| ASSI218 | Tanderagee | Co. Tyrone | | Details... |
| ASSI284 | Tardree Quarry | Co. Antrim | | Details... |
| ASSI070 | Tattenamona Bog | Co. Fermanagh | Tattenamona Bog is of special scientific... | Details... |
| ASSI011 | Teal Lough and Slaghtfreeden Bogs | Co. Londonderry | The area is of special scientific intere... | Details... |
| ASSI011 | Teal Lough and Slaghtfreeden Bogs | Co. Tyrone | The area is of special scientific intere... | Details... |
| ASSI088 | Teal Lough Part II | Co. Londonderry | Physiographical interest in the active p... | Details... |
| ASSI088 | Teal Lough Part II | Co. Tyrone | Physiographical interest in the active p... | Details... |
| ASSI277 | Tedd | Co. Fermanagh | | Details... |
| ASSI191 | The Cliffs of Magho | Co. Fermanagh | The Cliffs of Magho consists of a large,... | Details... |
| ASSI283 | The Gobbins | Co. Antrim | | Details... |
| ASSI320 | The Maidens | Co. Antrim | | Details... |
| ASSI082 | Tievebulliagh | Co. Antrim | Internationally important type site for ... | Details... |
| ASSI099 | Tieveshilly | Co. Down | Historically important exposures of grap... | Details... |
| ASSI129 | Tonnagh Beg Bog | Co. Tyrone | A large , relatively intact lowland rais... | Details... |
| ASSI052 | Toome | Co. Londonderry | Internationally important deposits of di... | Details... |
| ASSI233 | Torr Head | Co. Antrim | Torr head is the best exposure of metamo... | Details... |
| ASSI163 | Tow River Wood | Co. Antrim | Tow River Wood is one of the best exampl... | Details... |
| ASSI332 | Tower More | Co. Fermanagh | | Details... |
| ASSI118 | Tullanaguiggy | Co. Fermanagh | The Tullanaglare Mudstone Formation , fo... | Details... |
| ASSI130 | Tully Bog | Co. Tyrone | A compact, relatively undisturbed lowlan... | Details... |
| ASSI220 | Tully Hill | Co. Londonderry | The last Ice Age, 24,000 to 13,000 years... | Details... |
| ASSI216 | Tullyard | Co. Armagh | The two fields at Tullyard are managed a... | Details... |
| ASSI146 | Tullybrick Lough | Co. Armagh | Lying in a small interdrumlin wetland th... | Details... |
| ASSI321 | Tullyratty | Co. Down | | Details... |
| ASSI190 | Tullysranadeega | Co. Fermanagh | Tullysranadeega represents one of the m... | Details... |
| ASSI148 | Turmennan | Co. Down | Turmennan consists of a valley mire, whi... | Details... |
| ASSI199 | Upper Ballinderry River | Co. Tyrone | The Upper Ballinderry River is a fast-fl... | Details... |
| ASSI093 | Upper Lough Erne - Belleisle | Co. Fermanagh | This site is an integral element of the ... | Details... |
| ASSI071 | Upper Lough Erne - Crom | Co. Fermanagh | An integral area in southern Upper Lough... | Details... |
| ASSI090 | Upper Lough Erne - Galloon | Co. Fermanagh | This area in southern Upper Lough Erne i... | Details... |
| ASSI094 | Upper Lough Erne - Trannish | Co. Fermanagh | An integral element of the Upper Lough E... | Details... |
| ASSI084 | Waterloo | Co. Antrim | Low cliffs and foreshore show a near com... | Details... |
| ASSI201 | West Fermanagh Scarplands | Co. Fermanagh | West Fermanagh Scarplands has a diverse ... | Details... |
| ASSI107 | White Park Bay | Co. Antrim | Situated on the north coast of Co. Antri... | Details... |
| ASSI174 | White Rocks | Co. Antrim | White Rocks contains the type sections f... | Details... |
| ASSI188 | Whitespots | Co. Down | Whitespots is of geological interest on ... | Details... |
| ASSI131 | Wolf Island Bog | Co. Londonderry | A very large area of intact lowland rais... | Details... |
| ASSI102 | Woodgrange | Co. Down | The Irish type locality for the Woodgran... | Details... |
