The well by St Margaret's at Binsey, Oxon is linked to the legend of St Frideswide - patron saint of Oxford City.
So the legend goes, she was pursued by a suitor, Prince Alfgar of Mercia into the woods where she hid with her handmaidens.
Eventually, returning to the city whcih he was beseiging, Alfgar was struck blind.
However, beacuse she was a good and saintly women, she prayed to St Margaret of Antioch and St Catherine of Alexandria. A well sprung up - the same well at Binsey and curing the errent Prince in the process.
In tudor times it had (much like Holywell in Wales) become a centre for cures. It is reputed that it was visited by Henry VIII & Mary.
There may be some truth to the 'healing' adage as locally it is referred to as a 'treacle well'. 'Treacle' being corruption of a medieval word referring to a healing tonic which was drunk by the sick. The well is belived to have been the inspiration for the Treacle Well in 'Alicein Wonderland' by Lewis Carroll.
St Frideswide herself beame the patron saint of Oxford, founding the church which would become Christchurch. Her shrine, once destroyed in the Reformation, has been pieced together and is a magnificent edifice, complete with several foliate heads.