This section is from the book "Ancient Legends, Mystic Charms, And Superstitions Of Ireland", by Jane Francesca Wilde. Also available from Amazon: Ancient Legends, Mystic Charms, And Superstitions Of Ireland.
In Sligo there is a well called Tober-na-alt, beautifully shadowed by trees, the branches of which are thickly hung with all sorts of votive offerings from those who have been cured by the water; and miracle-men attended, who professed to heal diseases by charms, prayers, and incantations.
A man who had been born blind once recited his experiences there. " Oh, Christians, look on me ! I was blind from my birth and saw no light till I came to the blessed well ; now I see the water and the speckled trout down at the bottom, with the white cross on his back. Glory be to God for the cure." And when the people heard that he could really see the speckled trout, of course they all believed in the miracle. For a tradition exists that a sacred trout has lived there from time immemorial, placed in the well by the saint who first sanctified the water. Now there was an adventurous man who desired much to get possession of this trout, and he watched till at last he caught it asleep. Then he carried it off and put it on the gridiron. The trout bore the grilling of one side very patiently ; but when the man tried to turn it on the fire, the trout suddenly jumped up and made off as hard as it could back to the well, where it still lives, and can be seen at times by those who have done proper penance and paid their dues to the priest, with one side all streaked and marked brown by the bars of the gridiron, which can never be effaced.