The most striking aspect of Irish geography is the simple fact that Ireland is a reasonably large island, in fact the 20th largest on the planet. Irish primary school textbooks used to liken the island to a bowl, with a flat centre surrounded by hills and mountains along its shores. That is broadly true, albeit very technical. On the map, the island of Ireland looks like a well-worn teddy bear, defined by its relatively straightforward southern and Eastern shores in contrast with the far more rugged northern and especially western coastlines. In the field, much of Ireland does indeed look very green!
As a whole, the island of Ireland measures about 84,500km² (32,500 sq. mi), about the same area as Utah or Austria and somewhat larger than Tasmania. Of this total, 14,000km² (5,500 sq. mi) comprise Northern Ireland, the area that remains part of the United Kingdom.
Ireland's eastern coast looks at the Irish Sea, the body if water between Britain and Ireland. The Northern and western Coasts are on the North Atlantic Ocean, the next stop to the west being America, and to the north Iceland. The southern coast borders what is often called the "Celtic Sea", essentially the Western forecourt of the English Channel, separating Ireland from Brittany (Bretagne). The total length of Ireland's coastline is controversial (as it depends on the method of measurement), but is commonly estimated at about 3,200km (1,990mi).
As mentioned above, Ireland has a low-lying centre (the Midlands), with hills and mountains mostly spread around her shores. They reach only moderate heights, the tallest being Carrauntoohil (Corrán Tuathail) in County Kerry, at 1,038 meters (3,406 ft.). As a result of Ireland's climate, the island is exceedingly rich in water, including various type of wetland. The longest and most famous of Ireland’s numerous rivers is the Shannon (an tSionainn, 360.5 km or 224 miles), virtually bisecting the country. There are many loughs (or lakes), the largest being the 392km² (151 sq. mi) Lough Neagh in Northern Ireland.
Countless islands and islets are scattered around the coasts of Ireland, many of them very small. Over 200 of them were inhabited until the late 19th century, often with minute populations. At present, only about a dozen retain any permanent settlement.
The entire population of the island of Ireland is about 6.65 million, 4.75 million in the Republic of Ireland and 1.9 million in Northern Ireland. Although much of Ireland's population used to be rural, recent decades have seen a strong trend favouring the cities: 1.35 million live in Greater Dublin (just over half a million in the city proper), 300,000 in Cork Metropolitan Area and 385,000 in Belfast's Metropolitan Area.
There are many ways of subdividing Ireland geographically. Historically, the island was subdivided into 32 administrative units known as Counties, six of which make up Northern Ireland, 26 the Republic. Even more historically, they fall into four "Provinces" (Irish cúige/cúigí, a word literally meaning “a fifth”), essentially one to each cardinal direction. Their historical origins are most likely in the early 1st millennium AD, when Ireland's countless small and tribal kingdoms where complemented with regional and provincial entities. The Provinces are the most convenient entities to describe Irish geography, as they differ in geography, character and history and as they tend to be an explicit aspect of their inhabitants' identity to this day.
Leinster / Laighin
Although it is the second smallest of the Four Provinces in terms of area, Leinster, the Eastern province, has the largest and densest population and contains the largest number of counties (namely 12, the better-known ones including Dublin, Wicklow, Kilkenny and Meath). Defined by the banks of the Shannon to the west and the shores of the Irish Sea to the east, Leinster includes much of Ireland's flat and fertile midlands, with some hill country especially in its southern half, notably the Wicklow Mountains just south of Dublin. Important anchorages, all on the relatively straightforward East Coast, include Carlingford Lough, Dublin Bay and Wexford Harbour, major rivers are the Boyne (An Bhóinn), Liffey (An Life) and Slaney (Abhainn na Sláine). The largest of Leinster's cities is Dublin (Baile Átha Cliath), others include Kilkenny (Cill Chainnigh), Dundalk (Dún Dealgan) and Drogheda (Droichead Átha). Historically, Leinster has often been the focus of foreign powers' interaction with Ireland; as a result of this and its great fertility, it has a rich cultural heritage ranging from prehistory to the present.
Connacht / Connacht
Connacht is sometimes considered the “Wild West” of Ireland. It is the smallest of the provinces, with the lowest population, the lowest population density and only five counties. Its eastern limits are marked by the River Shannon and its lakes, to the north and west it is characterised by the rugged Atlantic shoreline, long stretches of it barely populated. The inland areas are reasonably flat, while the coastal areas have mountain ranges including the Ox Mountains, Nephin Beg and Mweelrea. The heavily indented shoreline features peninsulas like Connemara (the coastal part of County Galway), Erris and the Mullet in County Mayo, the famous Aran Islands, as well as Ireland's largest offshore island, Achill. Inlets include Galway Bay, Killary Harbour (Ireland's only fjord), islet-studded Clew Bay, the wild waters of Blacksod and Broad Haven Bay, as well as the funnel-shaped Bay of Killala. Connacht is well-watered: apart from rivers like the Shannon and Moy (An Mhuaidh), there are several large lakes, among them Lough Corrib, Lough Mask and Lough Conn, as well as expansive areas of blanket bog and other wetlands. Connacht's only city is Galway (Gaillimh), large towns include Sligo (Sligeach), Westport (Cathair na Mart) and Ballina (Béal an Átha). Due to its remoteness, Connacht has preserved much of the Irish tradition in music and storytelling; it also contains the largest number of active Irish speakers.
Munster / Mumhain
The largest of the Provinces, Munster occupies the island's south and southwest. It is subdivided into only six counties, including household names like Cork, Limerick, Clare, Kerry and Tipperary. Although Munster includes a very fertile part of the Central Plain, much of its south and west is rugged and mountainous, including the Galtees, the Derrynasaggart range and MacGillycuddy's Reeks, the highest rise in the country. The coastline is extremely indented, forming the peninsulas of Loop Head, Dingle, Iveragh and Beara, and inlets at the Shannon Estuary, Dingle Bay, Kenmare Bay, Bantry Bay and Cork Harbour. Rivers include the Shannon (most of its tidal part is in Munster), Lee (An Laoi) and Blackwater (An Abha Mhór). Among the better-known offshore islets are Valencia, the Blaskets and the Skelligs. The most important city is Cork (Corcaigh), other centres of population are found at Limerick (Luimneach), Ennis (Inis) and Killarney (Cill Airne). With its mixture of a fertile and river-fed inland and the rugged peninsulas of the West, Munster is like a miniature of Ireland, encompassing virtually all its landscape types, including the unique limestone “desert” of the Burren in County Clare, with a dense cultural heritage rivaling that of Leinster.
Ulster / Ulaidh
Ulster is the historical northern province of Ireland. It includes all six counties of Northern Ireland, which is part of the United Kingdom, but the use of the term “Ulster” for that entity is misleading: historically, Ulster also includes three counties that now belong to the Republic. Ulster is currently the poorest of the provinces in terms of per capita income. Ulster is very diverse in terms of landscape, including the northern part of the Central Plain, as well as parts of the western, northern and eastern coasts and the intervening mountains. Uplands include the Blue Stacks and Derryveagh range in County Donegal, the Sperrins across Northern Ireland, the Antrim Plateau in the northeast and the Mountains of Mourne at the border with Leinster. The coastline is complex, including multiple peninsulas, separated by Donegal Bay, Lough Swilly, Lough Foyle, Belfast Lough and Carlingford Lough. The coastal areas range from densely populated and industrialised in the east to virtually deserted and highly rural in the west. Offshore islands include Rathlin and Tory. The most important rivers are the Foyle (An Feabhal), Bann (Bhanna) and Lagan (Abhainn an Lagáin); Lough Neagh is the largest inland body of water in the United Kingdom and the combination of the utterly labyrinthine Upper Lough Erne and its Lower Lough Erne continuation makes for one of the most unusual landscapes in Europe. Ulster's main cities are Belfast (Béal Feirste), the capital of Northern Ireland, Derry/Londonderry (Daire), Ballymena (Baile Meánach) and Newry (An Iúraigh); in the Republic, the key population centres are Letterkenny (Leitir Ceanainn) and Donegal (Dún na nGall). Due to its close proximity to Britain, Ulster – especially its eastern part – has been recipient to much influence from Ireland's larger neighbour, while its western forelands and remote inland areas have stubbornly retained much of Ireland's native traditions. Ulster is a land of profound contrasts and conflicts, played out in a remarkably splendid natural setting.