Listverse has a list of ten discoveries that cast the vikings in a new light. It’s quite interesting and worth a read.
Why mention vikings on Saint Patrick’s Day? Mainly because they were instrumental in the development of the city of Dublin:
The Vikings explored vast amounts of Europe and North America, but they eventually settled into the land that would eventually become Dublin. At the time, its relatively mild climate, thick tree cover, and river made it the perfect location for a winter home. There they repaired their ships and set up a trade network.
The number of Viking relics found in Dublin over the years has been staggering. Temple Lane was created by Viking settlers and has been called the oldest street in Dublin. Viking swords have been found in the area around Christchurch, and the earliest foundations of Dublin Castle are clay floors that were also dated to the Viking era. And just south of the River Liffey is a huge concentration of buildings that seem to indicate the center of the Viking settlement, including houses and buildings once used for metalworking and the production of other commodities like leathers, textiles, and jewelry. Also along the area of the Liffey was evidence of amber-working.