Ireland, the second-largest island in Europe, lies in the Atlantic Ocean on the western periphery of the European continent, separated from Great Britain to the east by the Irish Sea. Although the island is 84,433 square kilometers (32,595 square miles) in size, the jurisdiction of the Republic of Ireland covers 70,280 square kilometers (27,135 square miles). With a population estimated at 3.97 million in 2004, Ireland remains relatively underpopulated with a population density of just fifty-six persons per square kilometer (22 persons per square mile), in contrast to the European Union (EU) average of 115 persons per square kilometer (44 persons per square mile).

Geographically, Ireland is a saucer-like territory, encircled by low mountains on the coast and relatively flat plains in the center. The country is divided into the four provinces—Connacht, Leinster, Munster, and Ulster—with these provinces further subdivided into thirty-two counties. Twenty-six of these counties constitute the Republic of Ireland; six of Ulster's...