Its history goes back to mesolithic man, some 7000 BC, see http://webcache.googleusercontent.com/search?q=cache:http://www.portaferry.info/History.html; with each stage or invasion represented, through religious changes, Norse, Cromwell. Strangford Lough itself is a Norse name -- Strang-fjord, says the site. If you have time to delve, there is a castle, and old church ruins.
Portaferry ferry, Strangford Lough toward Downpatrick, Ireland.
Portaferry does not go to Portadown, another place entirely. Portadown is a market town also with a long history, more prosperous since the 17th century, see http://www.portadowntown.com/about/heritage.asp. The "down" comes from old Gaelic for dun, or fortress, or fort. Place of the fort.
The Cathedral at Downpatrick displays the gravestone allegedly of Saint Patrick, see http://visitdownpatrick.com/, where Saint Patrick is said to be buried.
Down Cathedral, Downpatrick, Ireland
There is a large flat slabstone in front, with a depression where he is supposed to have laid his hands.
Saint Bridget, see http://marshallco.net/axtell/stbridget/bridget-life.htm; and Columba or Columcille are also here. See http://www.saintspreserved.com/Colum/St_Colum.htm.
Other sites have St. Bridget buried at Kildare. See http://www.ecole.evansville.edu/glossary/bridgeti.html. As to St Brigit, or St Brigid, or Brigid, she apparently is the Christianization of the old Celtic goddess of the same name in whose honor so many sacred wells, healing wells, are named. See discussion at http://irelandroadways.blogspot.com/view/flipcard#!/2006/06/magic-or-healing-wells.html