Ireland (Irish: Éire [ˈeːɾʲə]), also known as the Republic of Ireland (Poblacht na hÉireann),is a country in  Northwestern Europe  consisting of 26 of the 32 counties of the island of Ireland, with a population of about 5.4 million. Its capital and largest city is Dublin, on the eastern side of the island, with a population of over 1.5 million. The sovereign state shares its only land border with Northern Ireland, which is part of the United Kingdom. It is otherwise surrounded by the Atlantic Ocean, with the Celtic Sea to the south, St George's Channel to the south-east and the Irish Sea  to the east. It is a unitary, parliamentary republic.