 As of 2016, 4.8 million live in the Republic of Ireland, and 1.8 million live in Northern Ireland.Ireland is located in the north-west of Europe, between latitudes 51° and 56° N, and longitudes 11° and 5° W. It is separated from Great Britain by the Irish Sea and the North Channel, which has a width of  at its narrowest point.To the west is the northern Atlantic Ocean and to the south is the Celtic Sea, which lies between Ireland and Brittany, in France.