Ireland (Gaelic Éire), republic comprising about five-sixths of the island of Ireland. The country consists of the provinces of Leinster, Munster, and Connacht and part of the province of Ulster. The rest of Ulster, which occupies the northeastern part of the island, constitutes Northern Ireland, a constituent part of the United Kingdom. The republic has an area of 70,273 sq km (27,133 sq mi).

The eastern coast of Ireland is fairly regular with few deep indentations; the western coast is fringed by drowned or submerged valleys, steep cliffs, and hundreds of small islands torn from the mainland mass by the powerful forces of the Atlantic. The chief physiographic features are a region of lowlands, occupying the central and east central sections, and a complex system of low mountain ranges, lying between the lowlands and the periphery of the island. Among the principal ranges are the Nephin Beg Range in the west, containing Mount Nephin, 719 m (2,359 ft); the Caha Mountains in the southwest, containing Mount Knockboy, about 707 m (about 2,321 ft); the Boggeragh Mountains in the south, rising to 640 m (2,100 ft); and the Wicklow Mountains in the east, rising to more than 915 m (3,000 ft). Carrauntoohil, located in the southwestern section of the island, is the highest point in Ireland (1,041 m/3,415 ft above sea level). Numerous bogs and lakes are found in the lowlands region. The principal rivers of Ireland are the Erne and the Shannon, which are actually chains of lakes joined by stretches of river. The middle section of the central plain is drained by the Shannon, which empties into the Atlantic Ocean through a wide, lengthy estuary. Nearly half of the Shannon, above the estuary, comprises the Allen, Ree, and Derg lakes. All of Ireland’s principal rivers flow from the plain, and an interior canal system facilitates transportation.

The climate of Ireland is like that of other islands. Because of the moderating influence of prevailing warm, moist winds from the Atlantic Ocean, the mean winter temperature ranges from 4° to 7°C (40° to 45°F), approximately 14 Celsius degrees (25 Fahrenheit degrees) higher than that of any other places in the same latitude in the interior of Europe or on the eastern coast of North America. The oceanic influence is also pronounced in the summer; the mean summer temperature of Ireland ranges from 15° to 17°C (59° to 62°F), about 4 Celsius degrees (7 Fahrenheit degrees) lower than that of other places in the same latitudes. Rainfall averages 1,000 mm (40 in) annually.

The population of the Irish Republic in 2002 was estimated at 3,883,159, giving the country an overall population density of 55 persons per sq km (143 per sq mi). The population decreased from the 1840s, when about 6.5 million people lived in the area included in the republic, until about 1970, largely because of a high emigration rate. During the 1980s the population increased at an annual rate of only about 0.5 percent. In 2002 the rate was 1.07 percent. Some 59 percent of the population lived in urban areas in 2000.

The economy of Ireland has been traditionally agricultural. Since the mid-1950s, however, the country’s industrial base has expanded, and now mining, manufacturing, construction, and public utilities account for approximately 36 percent of the gross domestic product, while agriculture accounts for only about 10 percent. Private enterprise operates in most sectors of the economy. The gross domestic product in 2000 was $93.9 billion.