The capital of the Republic of Ireland, also sometimes called ‘Southern Ireland' or ‘Eire', is the city of Dublin, which stands at the mouth of the River Liffey. This reaches the Irish Sea midway down Ireland's east coast. The city spreads around Dublin Bay and includes busy cargo and ferry ports. The international airport is five miles to the north. Hire a car in Dublin and you'll find it is a big bustling city with normal rush-hour problems but that traffic is helped by the M50 motorway, looping from the centre right round the city, creating a ring road and enabling quick access in all directions.