Bloodbeard wrote:
One way of getting a rough idea is to check old maps, parish maps are good for this, of course your well might be much older than the oldest preserved map but it might give you a hint. I know of many wells here in Ireland that would have a 'Christian' lineage but are of course much older.
Thank you for your comment Bloodbeard (pirate?). I thought after I asked this question that it was probably spurious; wells are ususally as old as the land itself and it is only when communities discover them and use them that they attain a history. It seems to be a given that wells named after saints were probably in use and revered by pre-Christian communities and dedicating them to a 'saint' was the early Christian church's way of eliminating pagan beliefs. 