evidence: Northern Ireland, part of the United Kingdom, lying in the northeastern quadrant of the island of Ireland, on the western continental periphery often characterized as Atlantic Europe. Northern Ireland is sometimes referred to as Ulster, although it includes only six of the nine counties which made up that historic Irish province. [...] Northern Ireland occupies about one-sixth of the island of Ireland and is separated on the east from Scotland, another part of the United Kingdom, by the narrow North Channel, which is at one point only 13 miles (21 km) wide. The Irish Sea separates Northern Ireland from England and Wales on the east and southeast, respectively, and the Atlantic Ocean lies to the north. The southern and western borders are with the republic of Ireland.