From the early 17th to the mid 18th centuries (CE) customs stations were created on offshore islands in order to prevent the spread of foreign pests and diseases. These have augmented the growth of scientific research and have been accompanied by the creation of universities near all functioning harbors.
http://www.wesleyjohnston.com/users/ireland/past/pre_norman_history/iron_age.html - An in depth History of Celtic Ireland (OTL)
http://www.unc.edu/celtic/timemap/maps/atlas15.html - Ireland according to Ptolemy (Circa 150 C.E)
http://www.rootsweb.ancestry.com/~irlkik/ihm/ - Ireland's history in maps (OTL)