South Dublin South Dublin South Dublin () is a county in Ireland, within the province of Leinster, and the Dublin Region, a successor to County Dublin, from which its name derives. South Dublin County Council is the local authority for the county. The county contains both dense suburbs of Dublin and stretches of unpopulated mountain. In 2011 it had a population of 278,749, making it the third most populous county in the state. South Dublin has an area of 222.74 square kilometres. It is bounded by Dublin City (15 km to the north east), the River Liffey (separating it from Fingal to
Dublin Port Tunnel Dublin Port Tunnel The Dublin Tunnel (Irish: "Tollán Bhaile Átha Cliath"), originally and still commonly known as the Dublin Port Tunnel, is a road traffic tunnel in Dublin, Ireland, that forms part of the M50 motorway. The twin tunnels form a two-lane dual carriageway connecting Dublin Port, which lies to the east of central Dublin, and the M50 motorway at junction 2, close to Dublin Airport. The tunnels are in length and total project length of . It had final cost of approximately €752 million. The tunnel was officially opened on 20 December 2006; it was initially only open to