Dublin is the capital city of Ireland, and is not only the largest in both population and size, but it is also the center for administrative, political, economic, and cultural activities in Ireland. It is also the main transportation link between Ireland and the rest of the world, with direct flights to numerous United States, British, and continental European cities. It is also linked, via ferries, with Great Britain, but remains the only member of the European Union without a direct rail or automobile link with other member states.