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
Roads in Ireland that time, Ireland's main cities (Cork, Limerick, Galway, Waterford and Belfast) excluding Derry were connected to Dublin with motorways or with near-motorway standard roads. Dublin was the focus of some other major projects, such as the East-Link and West-Link toll-bridges, as well as the Dublin Port Tunnel. Major by-pass projects were also built around other cities and towns. The Jack Lynch Tunnel under the River Lee in Cork was a major project outside Dublin, and a fourth crossing at Limerick under the River Shannon (known as the Limerick Tunnel) opened in 2010. The different classes of roads in Ireland are