Dublin Bay of Dublin reach the Irish Sea at Dublin Bay: the River Liffey, with the River Dodder flow received less than 1 km inland, River Tolka, and various smaller rivers and streams. The metropolitan area of the city of Dublin surrounds three sides of the bay (the north, west, and south), while the Irish Sea lies to the east. Dublin was founded by the Vikings at the point where they were able to ford the River Liffey with the first wattle bridge up from the estuary. The city spread from its birthplace, around what is now the James's Gate area, out
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